1. Optimization of
Clevises
EAT40002 – Final Year Research
Project 2 (Eng. Bus.)
ALEX PARKER - 9519920
SUPERVISOR: KATHY PETKOFF & PROF STEVE WORTHINGTON
31/10/16
Executive Summary
In this research report, the author has investigated
using adhesives instead of welding to produce
clevises. The author has destructively tested to
determine the strength of each process, as well as
measure the dimensional accuracy of each. The
author has also determined the cost of producing
clevises with each manufacturing technique, using
real world costings.
Furthermore, the author has investigated what the
general public perceptions of using adhesives
instead of welding are, as well as those in the
Australian manufacturing industry
2. Alex Parker 9519920
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EAT40002 Coversheet for Final Report
Project group
number:
M Auto CRC Project
Title for Engineering: Optimization of clevises
Title for Business: Optimization of clevises
Students’
Names and IDs:
1) Alex Parker ID: 9519920
Eng. supervisors’
names:
Kathy Petkoff Bus. supervisor’s name: Steve Worthington
Date of
Submission:
31/10/16 Number of words in Report: 14000
DECLARATIO
We declare that ( the first four boxes must be completed for the assignment to be accepted):
□This assignment does not contain any material that has previously been submitted for assessment at this or any
other university.
□This is an original piece of work and no part has been completed by any other student than those signed below.
□We have read and understood the avoiding plagiarism guidelines at
http://www.swinburne.edu.au/ltas/plagiarism/students.htm and no part of this work has been copied or paraphrased
from any other source except where this has been clearly acknowledged in the body of the assignment and
included in the reference list.
□ We have retained a copy of this assignment in the event of it becoming lost or damaged.
□(optional) We agree to a copy of the assignment being retained as an exemplar for future students (subject to
identifying details being removed).
Student names: Signatures Date:
Alexander Parker 31/10/16
3. Alex Parker 9519920
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Declaration
This report contains no material which has been accepted for the award of any other degree or diploma
in any university or tertiary establishment, and to the best of my (our) knowledge and belief, contains
no material previously published or written by another person except where due reference has been
made.
Where a report has been professionally edited, the student must include separate acknowledgement
that such
“editing has been and the editing has addressed only the style and/or grammar of the report and not its
substantive content."
Students’ names Signature
1 –
2 –
3 –
4 –
4. Alex Parker 9519920
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Acknowledgements
The author would like to thank Excellerate Australia for funding this research, EVX for allowing this research to be
conducted on their behalf. Team Swinburne for sharing resources and contacts. Dr Clint Steele, Kathy Petkoff,
Barbara Evans and Steve Worthington for their guidance and support. Finally, the author would like to thank Patrick
Doherty and Steven Parker for their assistance throughout the project.
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11.4 Technical Staff .....................................................................................................................................................45
11.5 Destructive Testing..............................................................................................................................................45
Appendixes..................................................................................................................................................................46
12.1 References...........................................................................................................................................................46
12.2 Image Sources .....................................................................................................................................................48
12.3 Hysol EA 9309.3NA Epoxy Paste Adhesive Data Sheet .......................................................................................49
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Table of Figures
Figure 1: The Immortus...........................................................................................................................................................8
Figure 2: Team Swinburne 2015 FSAE Vehicle........................................................................................................................8
Figure 3: Tab and Slot Technique..........................................................................................................................................12
Figure 4: Temperature vs Distance from weld......................................................................................................................13
Figure 5 Shielded Metal Arc Welding....................................................................................................................................14
Figure 6: The Gas-Metal Arc Welding process......................................................................................................................11
Figure 7: Gas-Tungesten Arc Welding...................................................................................................................................12
Figure 8: Weld Defects..........................................................................................................................................................13
Figure 9: Welding Joins .........................................................................................................................................................14
Figure 10: Ideal Orthogal Cutting..........................................................................................................................................15
Figure 11: Horizontal (a) and Vertical (b) mill.......................................................................................................................18
Figure 12: Surface of samples (x 100 enlargement): a) milled surface, b)raw surface, c) surface after ..............................19
Figure 13: load vs Displacement ...........................................................................................................................................20
Figure 14: Thickness of Adhesive layer and strength............................................................................................................20
Figure 15: Self jigging............................................................................................................................................................24
Figure 16: TIG welding clevises.............................................................................................................................................24
Figure 17: CAD Image of Jigging Adhesive ...........................................................................................................................24
Figure 18: Adhesively joined clevis .......................................................................................................................................24
Figure 19: Testing Jig.............................................................................................................................................................25
Figure 20: CAD image of testing jig.......................................................................................................................................25
Figure 21: Adhesive Force v Extension Graph.......................................................................................................................27
Figure 22: Failure of Adhesive Clevis ....................................................................................................................................28
Figure 23: Calculating strength of a weld .............................................................................................................................28
Figure 24: Welding Force v Extension graph.........................................................................................................................29
Figure 25: Failure of welded clevis........................................................................................................................................29
Figure 26: CAD model of clevis .............................................................................................................................................30
Figure 27: Cost of Welding vs Adhesive................................................................................................................................31
Figure 28: Hobbyist exposure to welding .............................................................................................................................32
Figure 29: Professionals exposure to welding ......................................................................................................................32
Figure 30: Professionals views on using adhesives...............................................................................................................33
Figure 31: Hobbyist views on using adhesives......................................................................................................................33
Figure 32: Professionals strength question ..........................................................................................................................34
Figure 33: Professionals weaknesses question.....................................................................................................................34
Figure 34: Hobbyist level of schooling ..................................................................................................................................34
Figure 35: Failure of adhesive clevis .....................................................................................................................................35
Figure 36: TIG welded clevis .................................................................................................................................................36
Figure 37: Failure of welded clevis........................................................................................................................................36
Figure 38: Strength of Adhesive vs Welding.........................................................................................................................37
Figure 39: Cost of Welding and Adhesive .............................................................................................................................38
Figure 40: Professionals industries .......................................................................................................................................39
Figure 41: Semester 1 Gantt Chart .......................................................................................................................................43
Figure 42: Semester 1 & Holidays Gannt Chart ....................................................................................................................43
Figure 43:Project Gannt Chart ..............................................................................................................................................44
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Summary
In the following research paper, the viability of using adhesives for manufacturing clevises is investigated. The
author decided to investigate this area as a means to reduce the cost of producing clevises for the EVX’s vehicle; The
Immortus - a self-sufficient electric vehicle. A review of surface preparation, layer thickness and temperature was
conducted to gain a complete understanding of adhesives, as well as machining and welding. A knowledge gap is
identified in comparing strength of adhesives to welding and machining as well as the comparable price of the three
techniques and the dimensional accuracy. Upon finding this gap in knowledge surrounding strength, price and
dimensional accuracy, the author decided to conduct a case study ton investigate this.
To do this, the author has manufactured 10 welded and 10 adhesively bonded clevises. These clevises will be used to
determine the cost of producing each variety, the dimensional accuracy of each and the strength of each process.
Furthermore, the author has investigated what the general public perceptions of using adhesives instead of welding are,
as well as those in the Australian manufacturing industry.
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Introduction and Problem Statement
This study is being undertaken for EVX – a company that ‘Introduced the world's first bespoke high performance
passenger sports car powered by the sun’. EVX is also commercialising a retrofit conversion kit to enable current
petrol cars, light trucks and fleet vehicles to be converted from being petrol powered to plug-in hybrid or full electric
AWD. The aim of this paper is to validate adhesively joining aluminum instead of welding or machining. EVX has asked
for this research to be undertaken to determine if money and time could be saved in the building time of their
products. However, the comparable strength to welding and machining is unknown, as well as the cost. It is expected
for limited run production that adhesively joining will be cheaper, but the point that welding becomes cheaper is
unknown. EVX has also asked the author to investigate this.
If adhesively joining is proven to be as strong as a welded join, the technique will be validated on the Team
Swinburne 2016 Electric FSAE (Formula Society of Automotive Engineers) vehicle in the suspension clevis design.
The Team Swinburne project is for engineering and business student, and it allows the students to apply the skills
taught in the classroom, to a real world problem, that being an open-wheel electric race car. Formula SAE is a
worldwide competition. Teams are run entirely by the university students on the team. The students are
responsible to design build and compete with an open-wheeled racecar against other university teams. The
competition is split into two section static and dynamic events, which performance in each event being marked by
points.
The EVX vehicles and the Electric FSAE vehicle share many attributes. Both are performance vehicles and thus weight
is an important factor, more so for the FSAE vehicle as energy storage is limited, and not quickly replaced. While EVX’s
solar powered vehicle is planned to be a limited number vehicle the plan conversion kit is planned to be sold in large
numbers. To keep the price down for greater uptake by customers, the cost has to be kept low. The same is found in
the FSAE static costing competition, where the cheapest car if it was produced in a commercial sense wins the most
points.
The strength of the manufacturing technique will also need to be analysed, as all of EVX’s projects are road legal, the
performance will need to be adequate to withstand the daily drive, in all conditions and road surfaces. Additionally,
the manufacturing technique will need to with stand Team Swinburne performance requirements. It is critical that
the performance of these materials is well understood as any component failure could have catastrophic results for
the driver.
Furthermore, the tolerance of each manufacturing technique will need to be analysed to ensure it would meet
large scale manufacturing requirements by EVX. Tolerance is also important factor on a FSAE car, as each part is
designed to fit with another part.
Figure 2: Team Swinburne 2015 FSAE
VehicleFigure 1: The Immortus
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Research Questions – Objectives & Aims
In this research project the overall goal is to determine if adhesively joining materials is comparable in strength, cost
and tolerance to welding and machining. This goal can be achieved by a certain number of specific aims
1) Determine which adhesive to test.
Henkel is a world leader in providing adhesives for personal use as well as industrial use. Henkel has offices located
in Melbourne and a previous relationship developed between Team Swinburne and Henkel. An interview will be
sought seeking technical advice from Henkel in which adhesive should be used. The factors to be considered when
choosing adhesives, is shear strength and price.
2) To determine which manufacturing technique isstrongest:
To determine this, a clevis has been chosen to destructively test. The clevis has been chosen because the relatively
ease of designing one to match each manufacturing technique. To test this, a tensile testing machine will be used
to conduct a pull out test. With breaking force and deflection being recorded a strain graph will be obtained.
3) Which method has the best dimensional control:
To determine if joining metals with adhesives rather than welding or machining is viable, we have to also determine if
a similar level of accuracy can be determined. Dimensional control and required accuracy is vital in considering what
manufacturing technique an engineer will use when design their part.
4) Which method is most cost effective
For any manufacturing technique cost is always of consideration. The cost to make a part comes from fixed costs
such as- machinery and rent, as well as variable costs such as; labour and material. To determine if this
manufacturing technique is truly viable, the real life cost has to be determined and compared to welding and
machining.
5) Where is the cross over point?
The author will also investigate at what point in hours, taking in account variable and fixed cost, it becomes cheaper
to weld then adhesively join metals. EVX has asked for this to be investigated, as their current products are planned
to be released in limited numbers?
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6) Ideal applications for research findings
Of course for any research to be undertaken, there has to be a market for the expected results. A market will be
identified where adhesives joined clevises could be used. This will add value to the final verdict if its viable or not
viable.
7) Determining consumer opinions
Theoretically you can design your joining area to be as strong using adhesives as welding and vice-versa, however there
is draw backs with each technique. However, as most people relate adhesives to readily available glues like super glue,
they naturally do not trust adhesives as much as welding. Thus the author must research the opinions people have
about adhesives and to determine if there is any correlation between professions, education level and personal ability of
metal fabrication.
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Literature Review – Analysis & Discussion
In the following section a comprehensive literature review, which explores the latest papers in the field of the
project, is presented. Through this literature review a knowledge gap will be found and will lead to the basis of the
project. The topics chosen for the literature review are; Australian manufacturing industry trend, welding,
machining, adhesives, tolerance and cost analysis.
With the Australian manufacturing industry in a current state of down turn, the industry is looking to rebuild into the
power house it once was. A literature review will be conducted to determine where the focus is expected to be in the
future. A cost analysis will also be performed on each manufacturing technique to determine the feasibility of it
being well received in industry.
As this research project is based around adhesively joining metal and comparing the strength to more traditional
methods of machining and welding, a literature review will be conducted in these areas. For this research project to
successfully compare the methods, knowledge in how to prepare your joining areas for both welding and gluing will
be needed. Furthermore, knowledge in designing your part for welding is required. Finally, a literature review will be
conducted on tolerances and the correct procedures to measure.
4.1 Australian Manufacturing Industry Trends
The Australian manufacturing industry is currently experiencing a prolonged period of difficult trading conditions
with not only the global financial crisis but the decrease in demand in residential and commercial construction
affecting this (Manufacturing Taskforce 2012). With Australia’s relative high cost of labor and energy coupled with
geographically isolation, causing high shipping rates, Australia is at a disadvantage from the outset. The sector was
furthered disadvantaged with the strength of the Australian Dollar, eroding the profitability of export and import
competing goods. (Manufacturing Taskforce 2012). Smart manufacturing techniques could see a shift in the current
trend of Australia manufacturing industry.
A focus on advanced manufacturing will generate many opportunities for Australia and is seen as a smarter approach
for Australia (Willox, 2014). Innes Willox 2014 argues that advanced manufacturing isn’t a static approach but a
dynamic approach that is constantly being reviewed and revised and has no distinguishing feature, but is more about
creating value around the manufactured product (Willox 2014).
“Defining advanced manufacturing as an approach does not restrict opportunities to specific
sectors – any manufacturer in any sector can become an advanced manufacturer. It isn’t limited
to particular technologies, and it isn’t even limited to production.”
As explained by Willox; the agile and flexible nature of advance manufacturing production methods allow for
better and faster customisation and ‘one-off’ jobs for individual clients. The costs associated with producing
higher-value goods and one off jobs allow Australian business to neutralize the labour cost disadvantage, allowing
them to become competitive in the Australian Market.
This papers investigation into adhesively joining metals, and comparing the strength as well as the associated cost will
provide another method of increasing Australian businesses profit margins, and help make the Australian
manufacturing industry the industry it once was.
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4.2 Welding
Knowledge in the art of welding sheet metal is fundamental to the success of this investigation. With proper
welding knowledge the author will be able to test industry standard welds and make correct comparisons with
machining and adhesives. Numerous papers and textbooks have been written covering the methods involved
in the welding process. For this paper to obtain meaningful data, knowledge of weld fixturing as well as
suitable weld strength is required. This information can be found in the Structural Welding Code – Steel (AWS
D.1:2000). In section 5.22.6 the code recommends that any member that is to be welded should be held in
position with devices such as; bolts, clamps, wedges or other jigging equipment. Using these jigging methods
will allow for the welder to accurately weld the pieces together in the correct position and alignment.
While this process works well with large production numbers, for limited run parts or ‘one-offs’ the cost of
building and maintain jigging equipment can be avoided by using self-jigging techniques as described by Bralla
(Bralla 1999). Self-jigging allows the the assemble parts and filler method to hold together during the heating
cycle of welding without external fixtures. Self-jigging givers better dimensional control that what would be
obtained from the above methods, as well as eliminates costs of loading and unloading parts into fixtures
(Bralla 1999). The self-jigging chosen for this project, is the slot and tab method in figure 3 as described by
Denier. The tab and slot method while requiring minimal additional work at the initial design stages saves time
during the manufacturing time. The two parts set to be joint have a tab and a matching slot. The two pieces
are very easy to position and are relative to one-another. Once the parts have been positioned into their
correct position the assembly can be welded without any external fixtures or support. The elimination of
external fixtures saves time, material and therefore money (Denier 2015).
Figure 3: Tab and Slot Technique
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Most welding done in industry is fusion welding (Juvinall & Marshek 2012). Fusion welding is the process of creating
heat from an electric arc passing between an electrode and the surface creating temperatures of approximately
4400C. The heat causes the material to melt at the isolated surface and a filler is feed into the melt. Greater heat
intensity gives deeper penetration of the weld in more a more concentrated area. This results in less change in the
metallurgical structure, and lower stresses in the weld. (Bralla 1999).
To prevent oxidation of the molten metal two methods are used. The first method is the use of flux that is consumed
in the welding process. When consumed the flux releases a gas that shields the area from the atmosphere. The
second method involves the use of inert gas that is deposited through the gun into the area. The most common inert
gasses used are Helium, argon and carbon dioxide (Bralla 1999).
Figure 4: Temperature vs Distance from weld
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Listed below is a list of what you are most likely to find in a fabrication/manufacturing plant (Bralla 1999).
Shield Metal-Arc Welding (SMAW)
SMAW is a manual process where the electrode is in rod form. The rod is covered in flux with both being consumed at
approximately the same rate. The protective gas is created from the decomposition of flux. (Schey 2000). The below
figure 5 illustrates the shielding of arc welding.
`
There are a number of advantages and limitations of SMAW. The initial equipment investment is relatively small,
however post weld finishing is required to remove slag and clean the weld area. SMAW is able to weld a variety of
base materials from 1.6mm thick, though the operator skill requirements to use a SMAW efficiently, is high.
Figure 5 Shielded Metal Arc Welding
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Gas Metal-Arc Welding (GMAW)
GMAW also known as metal-inert gas (MIG), differs from SMAW by the delivery of shield gas and electrode. The
electrode of GMAW is fed continuously at a set speed from a coil into the guide tube. The wire is consumed during
the process and provides the necessarily filler. The gas is also feed to the area through tubing into the weld area,
providing the required protection from the atmosphere. (Schey 2000) Figure 6 below illustrates the GMAW process
GMAW has a number of advantages when compared to SMAW. Higher speeds and deeper pentration is possible.
Additionally, post weld cleaning is required, and operator skill required is less. GMAW is able to weld sheet as thin as
0.5mm up to large plate. (Bralla 1999).
Figure 6: The Gas-Metal Arc Welding process
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Gas-Tungsten Arc Welding (GTAW)
GTAW also known as tungsten-inert gas (TIG) welding is quite similar to GMAW. However, the electrode
does not supply the filler material and is therefore not consumed in the process. The filler material is
inserted by the user holder the filler wire; as seen in figure 7 below.
GTAW is able to produce a small intense heat source, that allows controllable melting of the material is
employed for precision joining of critical components with controlled heat requirements. GTAW is suited to
material less than 3mm, however a skilled labourers can weld 0.12mm. When material is larger than 6mm,
another process is chosen.
Figure 7: Gas-Tungesten Arc Welding
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Weld Defects
If any of the requirements for producing a sound joint are not met, various defects may occur. Defects can exist in
any weld of any geometry and origin.
If the melting process is not controlled according the following as seen in figure 8 can be seen. Figure 8a is a result
of lack of fusion and in thick base metals, incomplete penetration, underfulling is caused by insufficient rate of weld
metal deposition. Figure 8b shows the result of excessive heat with melt through being evident. Figure 8b also
demonstrates when rates of filler are high with overlap, the edges of which give a notch effect with reduced fatigue
strength. Finally figure 8c shows a good weld, with the join area being filled with filler.
Weld defects can also be caused by not preparing the bonding surfaces. If the surface has contaminants, including
oxides, oils dirt and other coating, it can result in lack of bonding.
In addition to issues raised above, the welds cracking is also a serious defect. Every crack is a defect no matter the
size (Regello 2012), and can often be attributed to the following:
Poor joint design
Incorrect machine settings
Incorrect shielding gas
Inadequate pre or post heat treatment
Extreme atmospheric conditions.
Regello explains that cracks must be dealt with quickly as they have the potential to negatively affect the mechanical
properties of the weld as well as expand throughout the weld. There are four types of crack defects the author will
need to be aware of, they being;
Figure 8: Weld Defects
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Hot Cracking – Appears shortly after welding and is caused by different cooling rates within the weld. Poor fitting
parts are often to blame for this, while the presence of Sulphur has also been attributed to this.
Cold Crack- Is induced by hydrogen being absorbed into the weld via the weld puddle. Another source of cold
cracking is contamination of the bonded area as discussed above. Unlike hot cracking; cold cracking won’t become
visible until the material has fully restored to room temperature.
Microfissure- is caused by metal fatigue or stresses in the heat affected zone (HAZ) a crack classified as microfissure
appears as the life of the weld deteriorates.
Crater Crack – It is standard practice for the welder to weld past the end of the joint, or to weld over the top to
prevent any cracks. If the operator neglects to do this a crater will be left behind where the welding stops, possibly
causing a crack to form in the material.
To avoid cracks appearing in the welds, Regello recommends the operators takes the following steps.
Spend time grinding and fillings the edges for easyfitting
Preheat joining area for thick plate
Using jigging equipment as explored above
Ensure machines settings are correct
While Regello doesn’t believe this will completely eliminate cracking, it is said the steps will help operators
avoid cracks and the required repairs, thus saving money.
Bralla argues that the welds can be strengthened and cracks avoided in the design stages of the produces, as
well as save time and money. (Bralla 1999):
- The butt join is the most efficient type of weld, and should be used where possible. (Figure 9)
- Minimizing the stress, the joint must carry is the most efficient and economical way for a strong welded part.
To do this Bralla recommends to locate welds away from areas of stress, or design the parts so that they and
not the welds carry theload.
- Grove welds should be in either compression or tension, while fillet welds should onlybe subject to
shear loads.
The above literature and recommendations will allow the author to design and manufacture a clevis that best meets
limitations of the welding technique for comparison with machining and adhesives. The literature also allows the
author to identify any potential cracking areas and make recommendation to the welder to avoid defects.
Figure 9: Welding Joins
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4.3 Machining
Machining is in generic terms, the process of cutting metal, it differs from the other manufacturing techniques as
the machinist starts with a solid piece of material and removes material to create the desired shape. Machining
is capable of creating geometric configurations, tolerances and surface finishes that is often not obtainable from
other processes. (Schey 2000).
As machining removes material that has already been paid for, it is often more expensive than other methods to
create the desired geometry, furthermore the set-up times can be lengthy and jigs are often required to mount the
work piece on the bed. For these reasons in mass production, machining is often used sparingly or if possible; not at
all.
To understand how machining processes work, it is important to understand exactly how material is removed from
the part. In the simplest case, the work piece is rectangular and cutting is performed at a rake angle α. Rake angle is
measure from the normal of the work piece to the cutting piece. Deformation of the chip is caused by shearing on the
shear plane inclined by shear angle ∅. The magnitude of the shear angle is fundamental. If the shear angle is small a
high cutting force and high energy is required to cut the material. Additionally, a high shear strain will be seen. Figure
10 illustrates the ideal case of Orthogonal cutting and equation (Schey 2000).
Where ∅ = Shear angle
rc = chip compression factor α =
rake angle
tan(∅) =
rc cos α
1 − rc sin α
Where rc = chip compression factor
h
rc =
c
=
lc
𝑙h
Figure 10: Ideal Orthogal Cutting
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ℎ = undeformed chip thickness
hc = formed chip thickness l = cut
length
lc = length of the chip
Υ = tan( ∅ − α ) + cot ∅
Where Υ = Shear Strain
𝐹 = 𝑃 𝑐 sin α + 𝑃𝑡 cos α
Where 𝑃 𝑐 = Cutting Force – acting parallel to the surface
𝑃𝑡= Thrust Force - acting perpendicular to the surface
Knowing your thrust force is important for the machine operator known as the machinist. Thrust force causes
deflection in the work piece, arising the requirement of support for long, slender or thin wall parts. Thrust force also
leads to deflection of the cutting tool and holder. If the force is high, these accumulative deflections can lead to
inability to achieve required tolerances. It is seen in the below equation that thrust force is a product of cutting
force and the difference in angle of friction and rake. As friction ψ decreases or as rake angle α increases thrust
force decreases. (Schey 2000).
Where ψ = friction angle
𝑃𝑡 = 𝑃 𝑐 tan( ψ − α)
In practise a machinist will set the tool at an angle to that of the work piece for several reasons. The chips will curl
into a helical rather than spiral and will more readily remove itself from the work piece. Secondly the effective rale
angle is less than that of a tool normal to the work piece. This lowers the cutting force and energy required (Schey
2000).
During the cutting process this energy is expended into a concentrated zone, with 80% of the generated heat being
taken by the chip, however the minimal heat rise seen in the work piece and tool, can result into dimensional change
(Schey 2000). To aid in heat removal as well as fulfilling two other major functions; lubrication and chip removal, a
cutting fluid is utilised.
At low cutting speeds lubrications aids in reducing rake face friction, increasing shear angle and therefore
reducing power consumption. At all speeds, lubrication reduces rubbing and in general, improves the surface
finish.
Cutting fluid reduces the temperature of the chip as it is removed as well as cooling the wok piece. This also allows
for higher cutting speeds compared to when no fluid is use. However, for the fluid to work efficiently and positively,
the entire cutting zone is need to be flooded with fluid, otherwise the tool and work piece will be exposed to a more
extreme temperature range.
Cutting fluid also aids in the removal of chips from the work area. It does this by flushing the chips are from the
zone and prevents clogging or binding of the tool.
There is a large variety of machining equipment available to the manufacturing industry. This literature review will
only look at milling, as this is the machining process that will be used to create the clevis.
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Milling is a versatile cutting process, with many varieties of cutting geometry, however, mills are classified by the
orientation of the tool (Schey 2000), with there being either horizontal (Figure 11a) or vertical (Figure 12b)
At Swinburne University, where the machining will be undertaken, there is only access to a 3 axis (x,y,z) vertical mill.
It is important to understand the limitations of a 3-axis machine when designing the clevises, and the fact that the
machine only has 3-axises of movement means that design of the piece will be quite simple.
Figure 11: Horizontal (a) and Vertical (b) mill
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4.4 Adhesives
The bonding of metal parts by adhesives is a growing practice, with aviation having used this technology extensively.
Adhesively bonding allows smooth, unbroken exterior surface, this is particular helpful for application where there is
fluid flow over the joint like aviation (Juvinall & Marshek 2012). Traditionally adhesives have also been employed in
preference to other methods;
When weight is of concern
Material is porous, fragile, or heat sensitive
Appearance is of importance.
Provide sound and/or vibration reduction
However adhesive bonding technology has advanced to the point that load bearing structures can be built upon the
technology, for which this class is termed as structural adhesives (Schey 2000). The structural joint is expected to
retain its load bearing capacity over a period of time while being exposed to environmental conditions. The adhesive
must have sufficient cohesive strength at application temperature and must be resistant to creep. During operation,
the adhesive must be able to distribute stresses, by being flexible this also assists in resistance to fatigue (Schey
2000). The joint must also be resistant to degradation by environmental factors it may be exposed to. Lastly the
adhesives viscosity has to allow the flow into the joint area, but not so low to be lost from the intended area. (Schey
2000)
To achieve a high quality structural joint, Schey 2000 recommends to spend considerable time on surface
preparation. Including cleaning the area of any organic substance, oils and grit, as well as increasing the roughness of
the surface area to be bonded. Surface preparation was also seen in Raykhere et al. 2010, who first cleaned the area
with acetone and subsequently roughened the bonding area with 200 grit sandpaper, roughness is desirable because
it gives a larger area of contract for the adhesive, with some research papers blasting the contact area with abrasive
material as described in Komorek & Przybyłek 2015. A comparison of surface samples can be seen in figure 12 below.
It was concluded that surface roughness was 4.28 µm due to the abrasive blasting. Although grit blasting resulted in
high adhesives strength comparer to raw surfaces, the grit of the media used to blast the surface caused no
difference in strength. (Harris & Beevers 1999).
Figure 12: Surface of samples (x 100 enlargement): a) milled surface, b)raw
surface, c) surface after
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There have been two areas of particular interest for researching in this field of recent, they being the effect of
temperature and adhesive thickness on the strength of the joint.
It is important to consider thermal effect because these can lead to a reduction in strength of the join. It was being
found before that the stresses caused by adhesive shrinkage has less effect on the strength than thermal mismatch of
material that are bonded. In comparison to most materials used structural applications, adhesives show dramatic
change in their mechanical properties. (da Silva et al. 2009). This study found that an increase in temperature
decreases the yield point, while a decrease in temperature increase the point of yield, as seen in figure 13 below.
It is clear from the above figure that temperature plays a crucial part in determining the failure point of adhesives.
The below figures 14 shows the findings of Abdullah, Afendi & Majid 2013, and their study on the thickness of the
adhesive layer. It was found that optimum thickness was 1.0mm where the highest load was seen. Beyond this point
a decrease was seen, until the plateau state was seen at 2mm thickness.
From this information it is clear during the manufacture of the clevises, layer thickness control will be required.
Figure 13: load vs Displacement
Figure 14: Thickness of Adhesive layer and strength
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To ensure the best performance from the adhesive Bralla 1999 recommends the following design
considerations
Design joint for shear, tension and compression, and if possible avoidpeel.
In lap joints, if the load paces the join in shear, the stress concentrateat the ends, therefore width of the
joint is more important than length.
Due to large shear stresses generated from thermal expansion if material expand at different rates,
expansion coefficients should be matched.
The accessibility to the joint is important to keep the joint clean.
Joints should be flat. Flat areas are easier to control thickness of the adhesive layeron.
Butt joints should be avoided if bond areas aren’t large due to adhesives
These design recommendations, as well as the above literature about temperature, surface preparation and the
thickness of the adhesive layer will all be fundamental to the success of this research.
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4.5 Tolerance
It is not possible to make the same part the exact same size each time. To overcome this, a maximum and minimum
size of the dimensions of the part has to be set, and this is known as tolerance. Different manufacturing techniques
have different tolerance ranges that are able to achieve, with the highest tolerance accuracy being the most
expensive, that is why it is good engineering practise to have your tolerance as wide as possible. (Boundy 2012)
The tolerance of the parts is presented to the manufacturer in the form of engineering drawings, in Australia we
follow the AS 1100 standard (Standards Australia 2016).
To be able to evaluate the best manufacturing technique, it is important to consider the level of tolerances
the technique can consistently obtain.
4.6 Cost Benefit Analysis
The main objective of a cost-benefit analysis is to estimate the gain and cost to the business, in hope to establish if
the project is worth the initial investment.
To meet the objective of a cost- benefit analysis all aspects of the project need to be expressed in terms of a common
unit, which is generally money. This can be expressed in either equivalent money value (if the has effect elsewhere),
or for this project, actual money value. Furthermore, to fully understand if there is a benefit or a loss, the money
value has to be expressed in current times, also known as Net Present Value (NPV). To achieve a likely real-world
outcome, a cost benefit analysis requires the valuation of benefits to be made under actual human behavior, that
being how the public valuate the benefit created and not what the analysist believes. (Watkins 2016)
Furthermore, the impact of the project needs to be studied, in both the situations of the project going ahead and
not going ahead. If the project is deemed to have an overall neutral effect to the greater business, is it worth the
risk to continue? Or if the projects NPV is less than that if the money was invested and earnt interest, is the project
worth the risk?
Parts that require to be machined can often be made at a lower cost by welding (Anon 2016). This is often true
however there is little literature on adhesively joining materials and the cost involved in this. To better understand
the costs involved with using adhesives a cost analysis will be performed and compared to welding and machining.
Cost analysis proves a complete accounting of expenses. To perform a complete cost analysis one needs to consider:
Direct costs
Indirect costs
Start up expenditures/one-time costs
Future costs
Capital costs
For this project, it will be assumed that future and capital costs equal zero. Start up/ one-time costs will be the price
to purchase machinery. Direct costs will be the price of the material as well as the cost of labour to manufacture this.
Once the cost of each is fully visualised, the will be used to help evaluate the viability of using adhesives to
manufacture clevises.
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Methodology
In this research project the best method of manufacturing clevis will be investigated. As suggested by Berns 1990 an
initial literature review will be carried out in two stages. During the first stage, an overview of the area is carried out.
Once the unknown is isolated, more specific journal articles will be reviewed. A literature review will assist the
author immensely in the success of this research project. It will assist the author by fully understanding what has
already been investigated in the related fields to this project, as well as determine what methods have already been
utilised to overcome issues.
On completion of the literature review, as seen above, an interview with Henkel; an adhesives manufacturer will be
conducted to determine which adhesive will best suit the needs of this project. The technical adhesive will be crucial;
however, the price of the adhesive will also play a role in this decision. A weighted table will be formed with
assistance from the projects industry sponsor; EVX.
Once the adhesive has been chosen with assistance the research will begin. The above
literature review will assist immensely for this; the design for experiments portion of the
research. From the literature the best loading conditions will already be known for each
manufacturing technique, and an adequate design will be made. It will also help keep the
tests consistent which will increase the authority of the research.
To determine the strength of the manufacturing methods a number of destructive test will be undertaken, and the
data gathered from this will allow a comparison on strength in double shear loading. The destructive tests will be
undertaken in the facilities at the universities structures lab, using one of their tensile testing machines.
Each sample is made from a generic design with similar geometry that is within the constraints of the
manufacturing technique. The data will be in the form of force vs displacement. The focus of this experiment will
be to determine what force the material can withstand before yield and failure occur. The displacement indicates
the stiffness or rate at which material deforms and allows material deformation regions to be depicted and
analysed.
Before destructive testing, each sample will be dimensionally analysed and the data recorded. This data will help
determine which method is able to produce the most dimensionally accurate piece. This information will be critical
to EVX, in determining if the adhesively joining materials is feasible for their products tolerance requirements.
Finally, a full cost analysis will be undertaken to determine which method is cheapest when taking in account,
equipment, skilled labourers, material as well as additional overheads. Additionally, this information will be used to
determine if and when the cross over point in time that producing products is cheaper then welding.
To decide upon which method is best when considering all of the above, a weighted table will be utilized. The
weighted table will be developed in conjunction with my industry sponsor; EVX, and literature. A weighted
table allows a user to combine results from different independent test, and combine them for an overall score
for each manufacturing technique.
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5.1 Manufacturing
10 sample of each clevis was manufactured, giving 20 samples to test. The design of the clevises was such that each
component was a 2D part that could be easily cut using either a waterjet cutter or laser cutter. Due to availability a laser
cutter was used to cut each part.
Each part was required to be filed to ensure not sharp edges could cut the users later on. Once this was completed the
clevises that were being welded were TIG welded (figure 15) . As discussed in the literature review, TIG welding is a very
technical process, and welding aluminum, is one of the most difficult materials to weld.
To make the welding process simpler, the clevises were self-jigged as described by Denier. The self-jigging technique
utilitsed can be seen in figure 16 below.
To manufacture each of the adhesive clevises, the self-jigging technique would not work. For adhesives to operate as
expected, a film layer has to be created, which according the literature above is 1 mm. To achieve this, a jig had to be
produced.
As can be seen in figure 18 the jig works by using the orange standoffs to position it, while the black piece holds its in
place. Once everything is in position, it is all bolted together, to allow the adhesive process to commence. The adhesives
chosen to test was a two-part Epoxy; Hysol EA 9309.3NA This was decided upon, after lengthy research and
conversations with Henkel’s service support. The Adhesive has ‘outstanding high shear and peel strength to aluminum’
(Henkel Corporation 2016) making it perfect for the testing that was being undertaken. The full specification product
sheet can be found in appendix 12.3
Figure 16: Self jigging Figure 15: TIG welding clevises
Figure 18: CAD Image of Jigging Adhesive
Figure 17: Adhesively joined
clevis
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Before the pieces were placed into the jig, they were sandblasted to ensure a consistent surface finish was achieved
between each sample. As found during the literature review stages of this project, the surface finish of the joining area is
of incredible importance of the overall strength of the final piece. Following this, the pieces were cleaned up, using wax
and grease remover to ensure no contaminates were present in the join area.
The two parts of the adhesive were then measures and mixed together. Once the adhesive was in place on the piece,
the object was baked for one hour at 82 degrees, to speed up the cure cycle. The adhesive can cure at room
temperature, but this is a lengthy process, and only a 3 jigging pieces were made, thus quick turnover was warranted.
5.2 Testing
The destructive testing was performed on a 50Kn Tensile and Compression machine in the Swinburne Structures Lab.
Each sample was being testing in the exact same way, to ensure consistency of the results.
The test jig was designed utilizing 40mm x 40mm steel bar. The test jig was then drilled and tapped so that each clevis
could be bolted onto the jig with 2 M6 Bolts. The maximum load was calculated to be within 13kN, and thus was
deemed that this jig would be strong enough to with stand multiple testing sessions. The testing jig was bolted to the
machine with 4 M10 bolts. The test jig also utilized a dynamic joint into the machine, so that minimal bending force will
be experienced by the testing machine. The test jig and clevis can be seen in figure 19 below.
Once everything was bolted into place the test program was started. The sample was subjected to 2mm/minute and
took approximately 5 minutes for each test to run. When the samples broke, the test was manually stopped and the
load and deflection data was automatically saved into a .cvs file for later analysis.
Figure 20: CAD image of testing jig
Figure 19: Testing Jig
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Change in Scope
This project has changed throughout the year, information which had previously not been obtainable, as well as
restrictions of scope, have had major influences on the projects progression. At the outset of this project, the tolerance,
cost and consumer opinions of welding, adhesives and machining were to be compared. It was decided as the project
progressed that the scope of this project was far too wide to be able to draw worthwhile conclusions on these topics
within the remaining 6 month of the year.
Further research into machining found that the time it took to machine a clevis and the expense of the equipment as
well as the wages to pay a machinist would make it uneconomical to machine clevises rather than weld.
This left the adhesive and welding comparison of clevises. This was seen as an opportunity to progress knowledge in the
field of joining materials. It also gave arise the opportunity to survey the population and determine what they think of
adhesives and welding, as well as the professional population. The authors previous experience working in the
Australian manufacturing industry and dealt with members from various areas of the Australian manufacturing industry
it became obvious that companies and the engineers who worked within them were unaware of potential savings of
using adhesives instead of welding for small run production.
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Results
In the following section, the results for engineering and business will be presented.
7.1 Engineering – Mechanical Performance
Adhesives
During the design phase of this project, the expected breaking load of the joint was calculated. Using the surface area of
the joint and the tensile lap shear data provided by the manufacture (Henkel Corporation 2016) it was calculated using
equation below to be 6.1kN
Length = 10mm
Width = 5.06mm
Depth = 3.5mm
𝐿𝑜𝑎𝑑 = 𝐴𝑟𝑒𝑎 𝑥 𝑡𝑒𝑛𝑠𝑖𝑙𝑒 𝑙𝑎𝑝 𝑠ℎ𝑒𝑎𝑟
During the testing phase, 10 adhesive samples were produced and tested. From the graph below, it is clear that the
adhesive clevis was unable to reach the expected load, with the average max load being 23% under the expected 6.1kN.
There could be a number of reasons for this, which will be explored in the discussion section. The maximum load seen,
came about in test 3, with a load of 5.5kN being recorded, however this was still 10% below the expected breaking load.
From the graph below, it can be seen that the majority of tests were very consistent with the extension and force
recorded, thus the film thickness, joint surface finish and the mix of the adhesives must have been consistent.
Figure 21: Adhesive Force v Extension Graph
Furthermore, the failure of the adhesive pieces was very consistent. As can be seen in figure 22 below.
-1
0
1
2
3
4
5
6
7
-0.5 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5
Force(kN)
Extension (mm)
Adhesives
Test 1
Test 2
Test 3
Test 4
Test 5
Test 6
Test 7
Test 8
Test 9
Test 10
Calculated
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Welding
Similar to the adhesives design phase, the expected load of the joint was calculated. Having a 2mm fillet weld the width
of the clevis (30mm) it was expected to break at 7.56kN, however, a miscommunication with the welder, resulted in a 5
mm fillet weld, which when recalculated would be able to withstand 18.91 kN
The welds strength was c the expected load of the joint was calculated, following the method outlined in Bralla 1999.
10 clevises were produced to be tested, however testing time was very limited, and only 6 was achieved. However, the
results obtained show a very consistent force and extension data as can be seen in figure 24 below.
Length = 30 mm
A = 2 mm
Tensile Strength = 240 MPa
𝐹 = (240 𝑥 106) 𝑥
30
1000
𝑥
2
1000
𝑥 cos 45
𝐹 = 7564.64 𝑁
Figure 22: Failure of Adhesive Clevis
Figure 23: Calculating strength of a weld
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From the graph it is clear the weld did not reach the expected load, this happened due to one unforeseen
circumstance, in the failure mode. It was found that the hole where the clevis was bolted to the rod arm, was elongating
and a material failure was occurring there. This can be seen in figure 25 below.
-5
0
5
10
15
20
0 1 2 3 4 5 6 7 8 9 10
Force(kN)
Extension (mm)
Welding
Test 1
Test 2
Test 3
Test 4
Test 5
Test 6
Expected
Figure 24: Welding Force v Extension graph
Figure 25: Failure of welded clevis
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7.2 Engineering – Dimensional Tolerance
Before the destructive testing was commenced, the dimension between the two upright pieces of the clevis was
measured. The CAD model below shoes that the two dimensions are 17.14mm
The adhesive manufactured pieced produced an average dimension of 17.04mm with a variance of .0.0054. Indicating
that on average, the upright pieces slightly angled inwards. The welded dimensions were as expected, indicating that the
upright pieces warped slightly outwards. This is due to the heat produced during the welding process. The welded
clevises averaged a dimension of 17.32mm with a variance of 0.040
7.3 Engineering – Cost Analysis
The cost was measures by tallying the individual costs for each manufacturing process. Thus the initial cutting was
ignored, as the slight difference in profile didn’t allow a significant change in cutting time, and therefore cost.
The initial cost of the welder was found to be $5480.53 from BOC (Anon 2016) and the other consumables that included
filler, tungsten tip, gas and miscellaneous objects totaled $4. Labour was set at AU $30.27 per hour (Anon 2016), which
came down to $4.41 set up and $0.22 per unit. This was calculated by using a stop watch, and timing the total time it
took to weld 10 units as well as the time it took to set up. It took the fabricator 10 minutes to set up, and 5 minutes to
weld 10 samples.
For Adhesives the yearly wage was reduced to minimum wage which is currently set at AU $17.70 (Anon 2016) as no
qualification or training is required to adequately complete this job. Adhesives came out to $1.48 a unit and
consumables was measured at $1.00. In total, to produce one unit using adhesives the cost was $13.60.
All this information was then used to find the payback price and the number of unit, being $14,996.56 or 1103 units
respectively. The full graph can be seen in figure 27 on the following page.
Figure 26: CAD model of clevis
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Figure 28: Hobbyist exposure to welding
7.4 Business – Survey Results
It was determined from the outset of this survey that there were to very distinctive groups of people who regularly
weld. The professional whom is currently employed or operates in the Australian manufacturing industry and the
hobbyist.
The objective of the commercial analysis is to answer the following research questions:
What are the thoughts of each group of people?
Will these consumers accept this new addition to the market?
As stated earlier, there are two distinct groups of people whom regularly undertake the welding process, be it Stick
Welding (ARC), Metal Inert Gas (MIG) or Tungsten Inert Gas (TIG). Consumer perception of the proposed innovation was
determined through an online survey. With each target audience being identified and distributed a different survey. Each
audience’s perception of adhesives and welding was gauged with key questions.
Evaluating the audience’s exposure to welding
Each survey questions the participates exposure to welding, be it at the work place or at home. The results of the
professional and hobbyist surveys can be seen in figure 28 and figure 29 respectively.
From this data, it is clear that the survey has been sent to the correct audience for each individual group. The hobbyist
survey attracted 31 responses, while the professional survey attracted 14 responses. Of the 31 response obtained by the
hobbyist survey, 61% of them have access to welding equipment at home. Similar to the hobbyist results, over 75% of
the professionals are exposed to at least half a day of welding at their workplace.
Figure 29: Professionals exposure to welding
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Perception of using adhesives.
Once the applicant’s exposure to welding was determined, the survey asked them, what their thoughts on using
adhesives instead of welding was. The research indicated that 85% of people surveyed that operate in the Australian
manufacturing industry, believe that using adhesives is a good alternative to welding. However, the research determine
that the hobbyist is unsure on the subject, with 65% saying they were unsure, or no they believe it’s a bad idea.
s
Figure 30: Professionals views on using adhesives
Figure 31: Hobbyist views on using adhesives
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Education of the participate
The final part of the survey, was constructed to assess the knowledge of the participate. As the professional survey was
sent to audiences whom have a bachelor degree at a minimum, their knowledge on the positives and negatives of
adhesives was tested. With the results showing that most knew the common strength and weaknesses of adhesives. The
hobbyist survey asked the respondents what level schooling they had completed, with 100% completing high school
degree or equivalent.
Further investigation found that results of hesitance about using adhesives could be related to a lower level of education.
Further research would need to be undertaken to fully understand this relationship.
Figure 32: Professionals strength question
Figure 33: Professionals weaknesses question
Figure 34: Hobbyist level of schooling
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Discussion
In the following section, the engineering and business results will be analysed thoroughly.
8.1 Engineering
The engineering section of the discussion, comprises of the adhesives and welding, dimensional accuracy and the cost.
Adhesives
Through the use of destructive testing, it was found that the adhesives failure mode was as expected. That is, they failed
in share, however it was at an average of 23% under what was calculated. There is a number of reasons why the
adhesive didn’t perform as expected.
As explored in the literature, it is essential that the surface of the joining area, is roughed up as well as clean. The joining
area was sandblasted, this would ensure that each sample had similar, if not the exact same surface roughness,
following this, the 3 pieces that make up the clevis was cleaned using wax and grease remover. Using wax and grease
remover, ensured that and debris left from the sandblasting was cleaned off, as well as any wax or grease was cleaned,
as this would also effect the adhesives ability to bond to the aluminum.
Following the preparation of the joining surface, the jigging system was used to lock each part into place. The jigging
would ensure that the film thickness of 1mm as specified from the literature.
Once everything is located and unable to move, the adhesive will be mixed. As this is a two-part adhesive, each part
must be measure accurately using scales. This was then thoroughly mixed, and placed onto the joining areas.
As stated above, the clevis underperformed when physically tested compared to the theoretical results. Furthermore, as
explored above there are many steps involved in producing an adhesive clevis. Possible reasons for the
underperformance could be that the joining area was not cleaned as thoroughly as first thought, or perhaps the mixture
ratio was incorrect, or the two parts were to mixed thoroughly.
Furthermore, on closer inspection of the photos and videos taken during the physical testing, it was found that the
adhesive was being exposed to peel. Peel is a significant weakness to most adhesives. While this adhesive in stronger
than most in peel, it is still significantly weaker than in shear. To eliminate the weakness of the peel, spacers should be
used between the spherical bearing in the rod end and the clevis. This is commonly referred to as a ferrule.
Figure 35: Failure of adhesive clevis
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Welding
Unlike adhesives, the failure mode of the welded clevises was completely unexpected. However, the performance of the
piece outperformed the adhesive version by approximately 300%. Initially the weld joint was calculated to be 7.56kN,
using a 2mm radius weld. Unfortunately, a larger; 4mm weld was placed, instead of the 2mm weld. This made the joint
twice as strong as expected. Ultimately it was a communication error between the author and the welder. However,
with stringent time management needed to finish the project in time, it was decided to test these.
The weld strength was recalculated and found to be 15.1kN, which was well within the strength of the all the fasteners,
jig and testing to be used.
As stated above, unlike the adhesive clevis, the welded joints didn’t break as expected. It was expected that the weld
would break well before the material broke. However, upon testing the samples, it was found that the hole where it was
connected to the rod end was elongating and eventually failing. This can be seen in Figure number below. The ultimate
failure was a ductile failure causing the material to deform, and yield before the weld broke. It can also be seen in Figure
Number that the heat affected zone was quite far away from this area, and had no influence on the material failure.
Ultimately, it was a design failure with the amount of material between the hole and edge being
inadequate. If this project was to be undertaken again, the author would recommend to leave more material in this
area.
Figure 37: Failure of welded
clevis
Figure 36: TIG welded clevis
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Comparable Strength
The comparison of the physical performance of adhesives and welding can be seen below, with the strongest of each
being displayed. It can be seen that welding out performs adhesives substantially, and the strength of the joint can be
easily increased without significant engineering or fabricator cost. In fact, the cost between welding a 2mm and 4mm
radius weld is so small, it would be considered zero.
Dimensional Tolerance
The adhesive manufactured pieced produced an average dimension of 17.04mm with a variance of .0.0054. Indicating
that on average, the upright pieces slightly angled inwards.
The variation seen with the welded samples were as expected. The welded clevises averaged a dimension of 17.32mm
with a variance of 0.040, this indicating that the upright pieces warped slightly outwards. This is due to the heat
produced during the welding process, and only fusing the materials together on one side. When welding pieces on both
side, warping is less likely to occur, with a skilled fabricator able to fabricate pieces so that no warping occurs.
Overall there is no process which has a clear advantage with joining aluminum. All dimensions were well within
tolerance for the purposed use of this research.
Cost Analysis
The cost, was found to be have a cross over point at $14,996.56, or 1103 units. The cost of each is made of employment
of someone with the ability to produce the required work, equipment and consumables. However, it did not include things
electricity, storage requirements of each as well as maintenance.
For a small business like EVX, who wishes to produce a limited run of vehicles, large savings are possible by using adhesives
instead of welding.
-2
0
2
4
6
8
10
12
14
0 1 2 3 4 5 6 7 8 9 10
Force(kN)
Extension (mm)
Adhesives vs Welding
Adhesives
Welding
Figure 38: Strength of Adhesive vs Welding
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8.2 Business
For the business aspect, the objective of this paper is to research the opinions people have about adhesives and to
determine if there is any correlation between professions, education level and personal ability of metal fabrication. It
was determined from the outset of this survey that there were to very distinctive groups of people who regularly weld.
The professional whom is currently employed or operates in the Australian manufacturing industry and the hobbyist,
and the results will be discussed in the separate groups.
Research revealed that hobbyist and professionals are open to the idea of using adhesives instead of welding, however
there is limited hesitance to the idea. Furthermore, primary research concluded that this may be due to limited
education on the industrial adhesives and their ability in consistently mixing a required ratio.
Professionals
This survey was constructed to determine what the professional whom is currently employed or operates in the
Australian manufacturing industry thoughts and knowledge of adhesives are. As manufacturing was the target industry,
it was promising to see 50% of respondents operated in this industry as seen in the figure 40
In addition to the survey reaching the correct industry audience, 60% of the respondents work for a business were
welding takes place at least half a day per week. Putting further authority on the relevance of the data.
The most surprising result of the data, is the overwhelming results of professionals believing adhesives are a good
alternative to welding. Respondents were also prompted to answer why they thought this, with the main reasons being,
skill, initial cost, training, surface finish, space required for welders and Occupational Health and Safety (OH&S) reasons.
It is also clear from the obtained data that the basic strength and weakness of adhesives is well known in the Australian
manufacturing industry, however there was some surprising results. With 36% of people response citing that in service
repair is a strength. However, this may be more of a misunderstanding between the writer of their survey and the
respondents, then an actual common belief.
OH&S or as it is now known as Workplace health and safety (WHS) was a surprising result, as it had not originally
occurred to the author as a strength of adhesives over welding. However, it should be noted that the adhesive used in
this research require a breathing apparatus, goggles and gloves to be used.
Figure 40: Professionals industries
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Hobbyist
The hobbyist survey was created to determine if a market would exist to use adhesives instead of welding for the person
who undertakes welding or other forms of fabrication at home. With 65% of responses saying that have access to
welding equipment at home, it was clear the survey was able to reach the intended audience. The survey also had a
great range of respondents, with a total of 31 people replying to the survey. The data collected indicated that wide
range of thoughts about using adhesives instead of welding, with many people signaling strength to be the main course
of concern.
The particular scenario of joining aluminum with adhesives instead of welding was a regular occurrence in the
comments, indicating the respondents have knowledge of the aluminum welding process and the difficulty in welding
aluminum. Furthermore, many respondents who did not have welding equipment’s at home, or did but didn’t know how
to weld, indicated that they would quite happily use adhesives.
Possible further reasons for the hesitance to using adhesives instead of welding may be the respondent’s thoughts on
their ability to consistency mix a 2-part adhesive. 30% of respondents felt they could not or were unsure on their ability
to consistently mix a required ratio.
While not prompted, some respondents left comments to further explain their choice. Upon reading this, it became
clear that that the point of concern was the accuracy. The comments left suggested that they felt they wouldn’t be able
to mix the required ratio exactly every time, but believed they would be within a margin of safety, that being 0.5-1.0%
over per 100 grams.
Following this, the respondents level of education was asked. This was done to determine if there was any correlation
between people not believing adhesives would be a good alternative to welding. It was found that people with a high
school degree of equivalent as their highest level of schooling did not think that adhesives would be a good alternative.
No compressive finding was determined with higher levels of schooling, as the responses varied from person to person.
45. Alex Parker 9519920
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Recommendations
If this research was to be undertaken again, or continued, the following alternative steps if undertaken would lead to
greater success.
Widen survey distribution to unknown acquaintance
The professional survey was distributed through established connections of the authors. These connections
were founded at previous networking events as well as their roles with Swinburne’s Formula SAE team - Team
Swinburne.
The hobbyist survey was distributed via social media, primarily Facebook. Facebook is the world’s largest social
media platform, with billions of people having a profile to connect and share content with their friend, peers
and other connections. However, one disadvantage of using Facebook is that its newsfeed is saturated with
large amounts of information that a post can become lost.
It would then be recommendable to all people wishing to investigate in the future, that the surveys be
distributed beyond the researcher’s initial circle of friends to unknown acquaintances.
Upgrade Survey Monkey in order to better elevate the options of an increased number of responses
With an increase in respondents achieved via the suggestion above, the survey development software that is
cloud based would require to be upgraded. Currently, each survey that is created using the free plan available
has a limit of 100 responses. Without an upgrade, significant amounts of possible data could be missed. In
addition to this, an upgraded plan allows for more robust surveying options, and significant advancements in
data analysis tools.
To further the research’s understandings, it is recommended to upgrade the Survey Monkey plan.
Publish test data with survey, to determine if strength was a key concern
To fully determine if people surveyed are opposed to adhesives or just unsure on its capabilities, the results
obtained from the physical testing should be published with the survey. This would allow people to understand
the potential of adhesives and welding more, and let them make a more informed decision.
46. Alex Parker 9519920
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Conclusion
From the beginning of this project, the author wished to optimizes the humble clevis. Not only was this information
going to be helpful of EVX and their pursuit of producing a road fairing vehicle, but also beneficial to Swinburne’s
Formula SAE team.
This research has shown that great savings can be made by using adhesives instead of welding for limited run
production. It has shown that while the welded clevises out performed adhesive clevises in mechanical properties, they
are still relatively strong. Furthermore, the research has shown that an additional period of engineering time could
produce a stronger adhesive clevis. The dimensional accuracy of each was within tolerances used on team Swinburne’s
FSAE vehicle and within the tolerances of a factory line produced vehicle.
The investigation into the general public’s perception, showed a lack of understanding of adhesives and their general
strength. More research would need to be undertaken using the recommendations found on page 41 to make a
definitive conclusion. It was also found that professionals currently working in the Australian manufacturing industry
have a deep understanding of the strengths and weaknesses of adhesives and have already investigated using them or
other methods instead of welding.
In conclusion the author has found that for limited run production, using adhesive sly bonded clevises would be superior
option if the required strength can be found. However, with the significant savings, engineering cost can increase to
create an intelligent design to further increase the bonding surface area.
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Milestones & Time Schedule
The entire timeline that has been establish thus far to date can be viewed in
Appendixes 10.2
10.1 Semester 1
The following is a plan for the first semester of the project. As this project is
Excellerate Australia (formally Auto CRC) funded, there are requirements that
have also been included, as well as other requirements that can influence the
amount of time spent on this project
10.2 Holidays
The below is the timeline for the university holidays, it can also be seen that the
work scheduled for semester 1 has been completed. There is work required to be
completed by the Swinburne technical staff and it is known to the author that there
can be a backlog of work requests in the latter half of second semester. For this
reason, physical testing will be completed in during the university break.
Figure 41: Semester 1 Gantt Chart
Figure 42: Semester 1 & Holidays Gannt Chart
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10.3 Project timeline
Below is the Gantt chart that was created at the outset of this project to ensure that the project ran smoothly and on
time.
As the year progressed and as more due dates became published they were added to the chart. In addition to this,
Excellerate Australia events were also added and as they directly affected the projects progression.
10.4 Project Reflection
The project did not go completely to the above chart. The physical testing was set to be completed in the university
holidays (June and July) as the availability of the equipment required was high. Furthermore, this would allow for proper
analysis throughout semester two, and to deliver a worthwhile conclusion to the research topic.
Many reasons can be pointed to as the cause of the delay in testing. The material took longer to purchase and receive
than first thought. This was also not on the timeline. Manufacturing the clevises was given a period of two weeks,
however this took 3 weeks, from the time the material was sent to the laser cutter to the time I got it back and all the
clevises had been welded and glued. Delays in getting availability with the testing machine also pushed the project
further back. However, when access was granted the testing was all achieved within 1 day.
Other issues that pushed the timeline out was the surveys. Each survey had to be ethically cleared before being allowed
to be sent out. Problems with getting ethical clearance for this particular subject seemed to be far greater than that of
other subjects. 2 weeks was given to create the surveys and a further 2 weeks was given to publish them. However, it
took 3 weeks for permission to be finally granted with the surveys and 3 weeks for an acceptable amount of responses
to be received.
Week Highlight: 39 Plan Actual % Complete Actual (beyond plan) % Complete (beyond plan)
PLAN PLAN ACTUAL ACTUAL PERCENT
ACTIVITY START DURATION START DURATION COMPLETE 4-Jan 11-Jan 18-Jan 25-Jan 1-Feb 8-Feb 15-Feb 22-Feb 29-Feb 7-Mar 14-Mar 21-Mar 28-Mar 4-Apr 11-Apr 18-Apr 25-Apr 2-May 9-May 16-May 23-May 30-May 6-Jun 13-Jun 20-Jun 27-Jun 4-Jul 11-Jul 18-Jul 25-Jul 1-Aug 8-Aug 15-Aug 22-Aug 29-Aug 5-Sep 12-Sep 19-Sep 26-Sep 3-Oct 10-Oct 17-Oct 24-Oct 31-Oct
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44
Example 1 5 1 4 50%
Workbook 10 13 0%
Online Modules 10 6 10 6 0%
Pick Area of Interest 10 2 10 1 100%
Reseach Plan 12 4 12 1 10%
Online Modules Due 15 1 15 1 100%
Research Plan Due 16 1 16 1 100%
Auto CRC Meet 17 1 17 1 100%
Perpare Presentation 16 4 16 4 100%
Presentation Due 20 1 20 1 100%
Perpare Progression Report 18 4 18 4 100%
Progression Report Due 21 1 21 1 100%
Workbook Due 22 1 22 1 100%
Auto CRC Poster 25 5 25 5 100%
Auto CRC Poster Presentation 30 1 30 1 100%
Talk to EVX 25 1 25 1 100%
talk to Henkel 25 2 25 2 100%
Purchase Adhesives 25 2 25 2 100%
Design Clevis 25 2 25 2 100%
Purchase Materials 25 2 25 2 100%
Cut DXF of Clevis 27 1 27 1 100%
Manufacture 27 2 27 2 100%
Work out time taken to manufacture 27 1 27 1 100%
Design Jig for Breaking 27 1 27 1 100%
Manufacture Jig 27 1 27 1 100%
Tolerance anaylsis 32 1 32 1 100%
Break Clevises 32 2 32 2 100%
Create Surveys 32 2 32 2 100%
Publish Surveys 34 2 33 2 100%
Excellerate Presenation 40 1 40 1 100%
Business Draft 38 1 39 1 100%
Engineering Draft 39 1 39 1
Business Submit 41 1
Engineering Submit 41 1
Main report Submit 43 1
Final Year Project
Figure 43:Project Gannt Chart
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Resources & Equipment
11.1 Literature
For the first part of this project; Scopus, Web of Science, Google Scholar, SAE Digital Library as well as physical books
in the Swinburne Library was used. This resources will still be required throughout the semester and into the testing
stage of this project.
11.2 Computer Aided Design Software
Computer Aided Design (CAD) will be required to design each clevis. Swinburne already gives students access to
Solidworks as well as compulsory CAD subjects so students become proficient in its use. Solidworks student
version has all the required features, that will be need to complete this project.
11.3 Material
This research project is sponsored by Excellerate Australia This has given the project access to $3000. These funds
will cover the cost of materials and any other project associated costs.
11.4 Technical Staff
As parts will need to be manufactured and tested, the technical staff will be required to waterjet cut the clevis
profiles. The technical staff will also be used to machine three clevises for testing. The technical staff Swinburne
has for students have years of experience and will be also be used for their expert advice. The welding and gluing
will be undertaken by myself with the facilities that Swinburne Formula SAE team have provided to them.
11.5 Destructive Testing
To obtain accurate results, this project will require the use of the machines in the structures lab, located in
Swinburne. Samples will be made of each manufacturing technique and then destructively tested in the Lab.
50. Alex Parker 9519920
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Appendixes
12.1 References
Abdullah, A, Afendi, M & Majid, M 2013, "Effect of adhesive thickness on adhesively bonded T-joint",
IOP Conf. Ser.: Mater. Sci. Eng., vol. 50, p. 012063.
Anon 2016, "BOC Smootharc Elite 230 AC/DC VRD TIG Welder Package | BOC Australia", Boc.com.au,
viewed 31 October, 2016, <https://www.boc.com.au/shop/en/au/boc-smootharc-elite-tig-230-ac-dc-vrd-
welder-package>.
Anon 2016, "Types of Economic Analysis - CBKB", CBKB, viewed 18 April, 2016,
<http://cbkb.org/toolkit/types-of-economic-analysis/>.
Anon 2016, "Tig Welder Salary (Australia)", Payscale.com, viewed 31 October, 2016,
<http://www.payscale.com/research/AU/Job=Tig_Welder/Hourly_Rate>.
Anon 2016, "Welcome to the Fair Work Ombudsman website", Fair Work Ombudsman, viewed 31 October,
2016, <https://www.fairwork.gov.au/how-we-will-help/templates-and-guides/fact-sheets/minimum-
workplace-entitlements/minimum-wages>.
Berns R., 1990, Introduction to Research Methods, 4th edition, Pearson Education Australia, Frenchs
Forest NSW 2086
Boundy, A 2012, Engineering drawing, McGraw-Hill Australia, North Ryde, N.S.W.
Bralla, J 1999, Design for manufacturability handbook, McGraw-Hill, New York.
Choi, C 2016, "Human Evolution: The Origin of Tool Use", LiveScience.com, viewed 15 April, 2016,
<http://www.livescience.com/7968-human-evolution-origin-tool.html>.
Choi, C 2016, “Human Evolution: The Origin of Toll Use”, LiveScience.com, view 15 April, 2016,
< http://www.livescience.com/7968-human-evolution-orgin-tool.html>
da Silva, L, Carbas, R, Critchlow, G, Figueiredo, M & Brown, K 2009, "Effect of material, geometry, surface
treatment and environment on the shear strength of single lap joints", International Journal of Adhesion
and Adhesives, vol. 29, no. 6, pp. 621-632.
Denier, S 2015, Tab and Slot Technique in the Jigging of Welded Sheet Metal Products, Bachelor,
Swinburne University of Technology, Melbourne Australia
Grant, L, Adams, R & da Silva, L 2009, "Effect of the temperature on the strength of adhesively bonded single
lap and T joints for the automotive industry", International Journal of Adhesion and Adhesives, vol. 29, no. 5,
pp. 535-542.
Harris, A & Beevers, A 1999, "The effects of grit-blasting on surface properties for adhesion",
International Journal of Adhesion and Adhesives, vol. 19, no. 6, pp. 445-452.
HE, D, SAWA, T & KARAMI, A 2009, "Stress Analysis and Strength Evaluation of Scarf Adhesive Joints with
Dissimilar Adherends Subjected to Static Tensile Loadings", Journal of Solid Mechanics and Materials
Engineering, vol. 3, no. 8, pp. 1033-1044.
51. Alex Parker 9519920
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Henkel Corporation, 2016, Hysol EA 9309.3NA Epoxy Paste Adhesive Data Sheet, Henkel, Bay Point, viewed 31
October, 2016, <http://www.mtpinc-exporter.com/chemicals/tds/Hysol%20EA%209309.3NA.pdf>.
Juvinall, R & Marshek, K 2012, Fundamentals of machine component design, John Wiley & Sons,
Hoboken, NJ.
Kalpakjian, S, Schmid, S & Kok, C 2008, Manufacturing processes for engineering materials, Pearson-
Prentice Hall, Singapore.
Komorek, A & Przybyłek, P 2015, "Initial Research of Impact Strength in Adhesive Joints", Solid State
Phenomena, vol. 237, pp. 160-165.
Lissaman, A & Martin, S 1982, Principles of engineering production, Hodder and Stoughton, London.
Manufacturing Taskforce, 2012, Smarter Manufacturing for a Smarter Australia, Commonwealth of
Australia, Canberra, pp. 1-117.
Regello, R 2012, "Weld Defects and How to Avoid Them", Welders Universe, viewed 26 May, 2016,
<http://www.weldersuniverse.com/weld_defects.pdf>.
Schey, J 2000, Introduction to Manufacturing Processes, 3rd ed, McGraw-Hill. Standards
Australia, 2016, Technical drawing Part 101: General principle, Sydney, NSW.
Standards Australia, 2016, Technical drawing Part 101: General principle, Sydney, NSW
Structural welding code--steel, American Welding Society, Miami, Fla.
Watkins, T 2016, "AN INTRODUCTION TO COST BENEFIT ANALYSIS", Sjsu.edu, viewed 26 May, 2016,
<http://www.sjsu.edu/faculty/watkins/cba.htm>.
Willox, I 2014, Advanced manufacturing: A smarter approach for Australia, Ai Group, Melbourne, pp. 71- 90,
viewed 17 May, 2016,
<http://www.aigroup.com.au/portal/binary/com.epicentric.contentmanagement.servlet.ContentDeliver
yServlet/LIVE_CONTENT/Publications/Reports/2014/CEDA%2520Advanced%2520Manufacturing%2520
AiGroup%2520final.pdf>.
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12.2 Image Sources
Figure 1: The Immortus – Photo courtesy of EVX
Figure 2: Team Swinburne 2015 FSAE Vehicle – Photo courtesy of Team Swinburne
Figure 3: Tab and Slot Technique - Denier, S 2015, Tab and Slot Technique in the Jigging of Welded
Sheet Metal Products, Bachelor, Swinburne University of Technology, Melbourne Australia
Figure 4: Temperature vs Distance from weld - Kalpakjian, S, Schmid, S & Kok, C 2008, Manufacturing
processes for engineering materials, Pearson-Prentice Hall, Singapore.
Figure 5 Shielded Metal Arc Welding - Kalpakjian, S, Schmid, S & Kok, C 2008, Manufacturing processes for
engineering materials, Pearson-Prentice Hall, Singapore.
Figure 6: The Gas-Metal Arc Welding process - Kalpakjian, S, Schmid, S & Kok, C 2008, Manufacturing
processes for engineering materials, Pearson-Prentice Hall, Singapore.
Figure 7: Gas-Tungesten Arc Welding - Kalpakjian, S, Schmid, S & Kok, C 2008, Manufacturing processes for
engineering materials, Pearson-Prentice Hall, Singapore.
Figure 8: Weld Defects - Regello, R 2012, "Weld Defects and How to Avoid Them", Welders Universe, viewed
26 May, 2016, <http://www.weldersuniverse.com/weld_defects.pdf>.
Figure 9: Welding Joins - Regello, R 2012, "Weld Defects and How to Avoid Them", Welders Universe, viewed
26 May, 2016, <http://www.weldersuniverse.com/weld_defects.pdf>.
Figure 10: Ideal Orthogal Cutting – Anon 2016, “Chegg.com”, Chegg.com, viewed 29 May, 2016
<http://www.chegg.com/homework-help/intoduction-to-manufacturing-processes-3rd-edition-chapter-16-
solutions-9780070311367>.
Figure 11: Mill – Grant, L, Adams, R & da Silva, L 2009, “Effects of the temperature on the strength of
adhesively bonded single lap and T joints for automotive industry”, International Journal of Adhesion and
Adhesives, vol. 29, no. , pp. 535-542
Figure 12: Surface of samples – Harris, A & Beevers, A 1999, “The effects of grit blasting on surface properties
for adhesion”, International Journal of Adhesion and Adhesives, vol. 19, no. 6, pp. 445-454
Figure 13: load vs Displacement -
Figure 14: Thickness of Adhesive layer and strength -
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12.3 Hysol EA 9309.3NA Epoxy Paste Adhesive Data Sheet
Hysol®
EA 9309.3NA
Epoxy Paste Adhesive
Henkel Corporation
Aerospace Group 2850 Willow
Pass Road P.O. Box 312
Bay Point, CA 94565 USA
925.458.8000
Fax: 925.458.8030
www.aerospace.henkel.com
Description
Hysol EA 9309.3NA is a toughened two-part paste adhesive. It contains 5 mil/0.13 mm glass beads for bondline
thickness control. Hysol EA 9309.3NA bonds metal skins and honeycomb core to yield tough permanently flexible
joints resistant to humidity, water and most common fluids. Its outstanding feature is high shear and peel strength to
aluminum.
Features
High Shear Strength
High Peel Strength
Bondline Thickness Control
Good Environmental Resistance
Uncured Adhesive Properties
Part A Part B
Color Pink Blue
Viscosity @ 77°F 3,000 Poise 0.2 Poise
Brookfield, HBT Spdl 7 @ 20 rpm Spdl 1 @ 60 rpm
(LVF)
Density 1.15 1.0
Viscosity @ 25°C 300 Pa·S 0.02 Pa·S
Brookfield, HBT Spdl 7 @ 2.1 rad/s Spdl 1 @ 6.3 rad/s
Warranty Life @ 77°F 1 year 1 year
This material will normally be shipped at ambient conditions, which will not alter our standard warranty, provided that
the material is placed into its intended storage upon receipt. Premium shipment is available upon request.
54. Alex Parker 9519920
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Hysol EA 9309.3NA
Henkel Corporation
Aerospace Group
Page 2 of 4
Handling
Mixing - This product requires mixing two components together just prior to application to the parts to be bonded.
Complete mixing is necessary. The temperature of the separate components prior to mixing is not critical, but should
be close to room temperature (77°F/25°C).
Mix Ratio Part A Part B
By Weight 100 22
Note: Volume measurement is not recommended for structural applications unless special precautions are taken to
assure proper ratios.
Pot Life (450 gm mass) 35 minutes
Method - ASTM D2471 in water bath.
Application
Mixing - Combine Part A and Part B in the correct ratio and mix thoroughly. THIS IS IMPORTANT! Heat buildup
during or after mixing is normal. Do not mix quantities greater than 450 grams as dangerous heat buildup can occur
causing uncontrolled decomposition of the mixed adhesive. TOXIC FUMES CAN OCCUR, RESULTING IN
PERSONAL INJURY. Mixing smaller quantities will minimize the heat buildup.
Applying - Bonding surfaces should be clean, dry and properly prepared. For optimum surface preparation consult the
Hysol Surface Preparation Guide. The bonded parts should be held in contact until the adhesive is set. Handling strength
for this adhesive will occur in 12 hours @ 77°F/25°C, after which the support tooling or pressure used during cure may
be removed. Since full bond strength has not yet been attained, load application should be small at this time.
Curing - This adhesive may be cured for 3 to 5 days @ 77°F/25°C or 1 hour @ 180°F/82°C to achieve normal
performance.
Cleanup - It is important to remove excess adhesive from the work area and application equipment before it hardens.
Denatured alcohol and many common industrial solvents are suitable for removing uncured adhesive. Consult your
supplier's information pertaining to the safe and proper use of solvents.
Bond Strength Performance
Tensile Lap Shear Strength
Tensile lap shear strength tested per ASTM D1002 after curing for 5 days @ 77°F/25°C. Adherends are 2024-T3 alclad
aluminum treated with phosphoric acid anodizing per ASTM D3933.
Typical Results
Test Temperature, °F/°C psi MPa
-67/-55 4,000 27.6
77/25 4,200 28.9
180/82 1,000 6.9
After Exposure to the Following conditions*:
Typical Results
psi MPa
Control, 77°F/25°C 4,800 33.1
77°F Water - 30 days 4,700 32.4
120°F/49°C - 98% RH - 30 days 5,100 35.2
Hydraulic Oil - 7 days 4,600 31.7
JP-4 Fuel - 7 days 4,700 32.3
