1. Karl H. Andreasson
Mattias Linder
Victor Persson
Joakim Skön
6/4/2015
Demonstrating the
Benefits of X-TECHTM
Chalmers University of Technology
Department of Product and Production Development
Product Development Project, MPP126
Academic year 2014/2015
2. Abstract
InXide AB, founded in 2012 and located in Trollhättan Sweden, has developed three patented
technologies. All based on integration of continuous fiber reinforced composites, one of these
is the X-TECHTM
technology, which is briefly described as continuous fibers over molded by
a thermoplastic matrix material.
This report aims to describe an extension of the governmentally funded FFI-project within
automotive safety, in which InXide collaborated with Klippan Safety and Swerea Sicomp. In
the FFI-project a demonstrator for X-TECHTM
, was developed to highlight the advantages of
the technology. The developed demonstrator was a cargo barrier designed to fit the current
Volvo XC70 model. This report describes the development of a second demonstrator for the
technology.
The application identified was a load retention eye, fitted in the trunk of the all-new Volvo
XC90, which is used to secure cargo when the vehicle is moving. In collaboration with InXide
and Volvo Car Corporation the project group carried out the development of this demonstrator
within the course MPP126 – Product development Project, as part of the M.Sc. Product
Development program at Chalmers University of Technology, during the academic year
2014/2015.
The development efforts were divided into two different Tracks. Track 1, which focused on
replicating the current design to enable quick implementation. Track 2 focused on
highlighting the benefits of the technology by fundamentally redesigning the product around
X-TECH™.
The Track 1 efforts resulted in a concept with similar appearance as the current solution,
however with a 57% lower weight, reduced CO2 emissions of 63% over the product lifecycle,
and an estimated cost reduction of 24%. These achievements have led to the concept receiving
positive feedback and attention internally at Volvo Car Corporation.
Track 2 resulted in two different concepts: The Logo and the Bar. The Logo, an innovative
concept paying homage to the Volvo brand, demonstrates the freedom of design associated
with X-TECHTM
and reduces the weight with approximately 70%, compared to the current
design. The Bar, on the other hand, is a simplistic concept demonstrating how weight
efficient, yet with high technical performance, a design can be if utilizing the technology with
weight savings of approximately 80%.
The findings are interesting, from a business perspective, both for InXide and Volvo Car
Corporation. As both parties see an implementation of the product as a possibility the project
group have recommended InXide and Volvo Car Corporation to initiate a pre-study in order
to verify the production process and supply chain.
3. Acknowledgements
We, the project group, would like to express a special thanks to a number of people whose
support has been of great value throughout the project. First, we would like to express our
gratitude to our supervisor, at Chalmers University of Technology, Johan Malmqvist. He has
guided us with his expertise and experience within product development. We would also like
to express gratitude to our contact person at InXide AB, Anders Holmkvist, who has
answered all stupid questions and with patience provided support of great value throughout
the project.
Further we would like to thank Birger Svensson and Patrik Lindroth at Volvo Car Corporation
for their engagement and interest in this project. Also, we want to thank Erik Marklund at
Swerea Sicomp for support within FEM simulations. Finally, without the help from Håkan
Johansson at APP Models and Martin Andreasson at InXide, production of the final
prototypes would not have been possible.
4. Terminology
CAD Computer Aided Design
DIN standard German industry standard
FEM Finite Element Method
FMEA Failure Mode and Effects Analysis
FFI Fordonsstrategisk Forskning och Innovation
"Strategic Vehicle Research and Innovation"
ISO standard International Standard Organization
LCA Life Cycle Assessment
Prepregs The fibers used in the process, prior to
impregnation.
SWOT analysis Strengths, Weaknesses, Opportunities, and
Threats analysis
VCC Volvo Car Corporation
SUV Sport Utility Vehicle
7. 1 | P a g e
1 Introduction
This report is describes the work and the results of the Product Development project
undertaken during the first of two years in the MSc of Product Development program at
Chalmers University of Technology. This report is based on the report written by the project
group (The project group, 2014) during the pre-study which was part of the course Product
Planning-Need & Opportunities, during the fall semester of 2014. The work has been carried
out by a group of X students during the spring semester of 2015. The project undertaken was
to develop a new demonstrator of InXide’s patented X-TECH™ technology.
This project is an extension of the governmentally funded FFI-project within automotive
safety, in which InXide are collaborating with Klippan Safety and Swerea Sicomp. In the FFI-
project a demonstrator of the X-TECH™ technology is being developed, a re-designed cargo
barrier for the Volvo XC70. The purpose of this demonstrator is to highlight the properties
obtained and the design possibilities when working with the X-TECH™ technology.
In the pre-project planning phase, carried out during the fall semester of 2014, five
opportunities were identified. This report covers the selection and development of the
opportunity which was deemed most promising for designing a good demonstrator application
of the X-TECH™ technology.
1.1 InXide AB
InXide AB was founded in 2012, as a spinoff from the research facility; Ecole Polytechnique
Federale de Lusanne, in Switzerland. The company recently released their first product to the
market, a drone aimed for professional use within landscaping. The drone may be used to map
the terrain and create 3D maps over vast landscapes, InXide manufacture the body of the
drone. The head office is currently located in Trollhättan, Sweden, InXide also have
production facility in Örkeljunga, Sweden and research in Lusanne, Switzerland. The
company currently employs eight people, where of five are positioned in Trollhättan, one in
Örkeljunga and Two in Lusanne. InXide offer three different technologies based on the
concept of reinforcing plastic materials with continuous fibers. All three technologies are
protected by a patent, which hence will be referred to as the X-TECH™ patent. The
technology treated in this report is also called X-TECH™ and consists of an injection molded
thermoplastic component, reinforced with a skeleton of continuous glass or carbon fibers. The
fibers are laid out, continuously through pultrusion, layer by layer until the desired skeleton
thickness is achieved. One of the unique features with the X-TECH™ technology is the high
strength to weight ratio, when exposed to tension loads. This, combined with possibilities of a
cost efficient and rational production process for large and mid-size volumes makes the
technology unique on the market today.
1.2 Aim and Scope
The aim of this project is to develop a new demonstrator of the X-TECH™ technology.
Moreover this demonstrator is to be developed in collaboration with a potential future
customer, demonstrating the properties of X-TECH™ to that company. The demonstrator is
to have properties which are as similar as possible to that of a mass produced component,
demonstrating both mechanical properties and aesthetical properties. The demonstrator will be
designed and tested by using CAE-software, prior to prototype production. Produced
prototypes are to be tested in order to demonstrate the mechanical properties of the
demonstrator.
8. 2 | P a g e
The limitations which frame the project are:
A set project budget of 60 000 SEK.
The time limits are constrained by the 7.5 credit course PPU085 Product Planning -
Needs and Opportunities and the 15-credit course MPP126 Product Development
Project carried out on the MSc program of Product Development at Chalmers
University of Technology, Gothenburg, during spring semester of 2015.
A project team size of four students.
The project is limited to include development and testing of the first generation of
prototypes.
1.3 Overview of Report
The report aims to create an understanding of the project and its process, used methodologies
and reflections made during the executions, as well as deliverables and conclusions.
In chapter 2, Technology, the reader will have an introduction to X-TECHTM
, its advantages,
drawbacks and the related production processes. If proceeding to chapter 3, Need for a new
product, the project will be justified by a description of why a new product is needed, from
the perspective of InXide as well as VCC. Chapter 4, Method, describes the methodology
framing the development efforts carried out. In chapter 5, Opportunity Selection, business
cases for identified opportunities as well as the selection and verification of opportunity are
presented. Finally, the chosen demonstrator application is described.
Chapter 6, Product Concept, describes the development efforts of the different concepts, and
chapter 7, Detail Design & Prototyping, guides through the component design and production
of prototypes for the concepts. In chapter 8, Commercial assessment, the market and the
business opportunities from the views of both VCC and InXide for the application are
discussed. After this, chapter 9, Results, describes the main achievements from the
development efforts. The efforts are tied up in chapter 10, Conclusions. Recommendations
and a concluding action plan are found in chapter 11, Recommendations, and chapter 12,
Concluding Action Plan, respectively.
References to literature, interviews and homepages are found in chapter 12, References. The
reader will, throughout the report, be advised to pictures, tables and graphs in the Appendix
for further information. These are found in Chapter 14, Appendix.
9. 3 | P a g e
2 Technology
The project group has been granted permission to include this section from the pre-project
planning report, by the authors.
The technology which this project concentrates on is the X-TECH™ technology, Figure 1,
which is patented by InXide. The X-TECH™ technology consists of an injection molded
thermoset body with a reinforcing continuous fiber skeleton. The skeleton matrix consists of
either glass fiber, carbon fiber or a mixture of both, together with a thermoplastic such as
polyamide (PA) or polypropylene (PP). X-TECH™ is a lightweight composite that has the
potential to compete with more conventional lightweight materials in a wide range of
applications. The most important aspect when designing components utilizing the X-TECH™
technology is to make sure loads are transformed into tension loads. The load is then
distributed evenly along the continuous fibers. X-TECH™ is resistant to corrosion and
additives can be added to improve properties such as UV-resistance.
Figure 1. The X-TECH™ technology; showing a cross-section view where
the reinforcing skeleton is visible (InXide, 2014).
One of the industries where the X-TECH™ technology has a great potential to compete is the
automotive industry, where the technology can take market shares from heavier and/or more
expensive metallic materials and their and alloys. An investigation using the software CES
EduPack focused on identifying materials which might compete with X-TECH™ revealed the
following materials; stainless steel, aluminum alloys, titanium alloys, magnesium alloys as
well as other polymer composites.
The specific application which was closely examined in the pre-project planning report (The
project group, 2014) was a cargo barrier. The cargo barrier is today made of stainless steel
which, compared to X-TECH™, is heavy. Since the automotive industry strives towards
reducing weight, in order to reduce emissions, the X-TECH™ cargo barrier with its similar
properties in tension loading and lower density is a possible replacement for heavier
materials. For instance the EU 2021 emission regulations state that any vehicle fleet offered
on the European market may not produce more than 95 g CO2 /km (European Commission,
2015), which will require substantial weight reductions. Just like the cargo barrier examined
in the pre-project report (The project group, 2014) the load retention eye, which is redesigned
10. 4 | P a g e
in this report, is an automotive safety detail manufactured from a metallic material. The load
retention eye is manufactured from molded zinc and is thus both heavy and costly. Another
reason for using X-TECH™ technology is the freedom of design offered by injection
molding, which allows advanced geometries and aesthetic designs which would be impossible
to manufacture with a metallic materials at a reasonable price. The identified competing
materials are discussed in the pre-project report (The project group, 2014).
2.1 Continuous fiber reinforced composites
Three main manufacturing technologies are available for continuous fiber reinforced polymer
composites. All three utilize the pultrusion process described in Figure 3 but do however use
different types of prepregs and are suitable for different types of applications. The first and
oldest technology uses pre-impregnated tapes; these tapes are either heated in a form and
shaped after the desired geometry, or used in a pultrusion process, see Figure 2. This method
is adaptable to a wide range of thermoplastic materials and can be used with both carbon and
glass fibers as reinforcement. The downside is the cost of pre-impregnated tapes and the fact
that they have a high stiffness and are not particularly flexible (Knox, 2001), they do however
provide high quality results.
The second technology can be referred to as comingling of fibers. In this process dry fibers
are mixed and heated until wetting of the reinforcing fibers is achieved. This process can be
carried out in one or two steps, depending on how the fibers are mixed. The two-step
alternative consists of first mixing the dry reinforcing fibers and thermoplastic fibers onto a
roll. This roll will in the second step be fed through an oven where the fibers are heated and
wetting occurs. The one-step alternative consists of using two separate rolls, one consisting of
dry reinforcing fibers and the other of thermoplastic fibers. The fibers are fed from these rolls
through an oven, where wetting occurs (Holmkvist, 2014). This method is called pultrusion
and is especially suited for large volume production with little variation between components.
Comingling of fibers offers greater freedom, compared to using pre-impregnated tapes since
the fibers have low stiffness. The comingled fibers can be used in a variety of manufacturing
processes including Bag Inflation Molding (BIM) and pultrusion (Knox, 2001).
Figure 2. To the left; Roll of prepreg carbon fiber tape,
to the right; rolls of prepreg carbon fiber yarn (Zoltek, 2014).
The third technology is the most advanced, enforcing fibers are fed through a heated low
viscosity thermoplastic which wets the fibers and cools as the heat source is removed (Knox,
2001). This manufacturing technology is challenging since thermoplastics have a high
11. 5 | P a g e
viscosity. This means that the viscosity needs to be lowered, either by using additives or
controlling the process in an advanced way. Today pultrusion is the method used, however it
would be desirable to move into using injection molding tooling. An obstacle which needs to
be overcome, whether pultrusion or injection molding is used is shrinkage. The thermoplastic
material shrinks between 10-15 % while curing, mold and process designers must keep this in
mind (Alfredson & Holmkvist, 2014). Research is currently being carried out by The
Fraunhofer institute concerning the use of Resin Transfer Molding for this process
(Fraunhofer, 2012).
Figure 3. The pultrusion process; 1) Rolls of continuous fibers, 2) Tension roller, 3) Impregnation bath, 4) Impregnated
fibers, 5) Heat source (oven), 6) Pull mechanism, 7) Hardened composite material (Lieshout, 2014).
12. 6 | P a g e
3 Need for a New Product
As this project can be viewed from both InXide’s and Volvo Car Corporation’s perspective
and will be quite different depending on which perspective is taken, both are included in this
chapter.
3.1 InXide’s Perspective
As a start-up company trying to establish a foothold on the composite market InXide have
identified two main areas of application; namely the automotive industry and the sports &
leisure industry. The product developed in this project fits the first of the two application
areas. The reason behind focusing on these two fields is due to their different natures, when it
comes to product implementation and contract-writing, as will be explained in the following
sentences. The sports and leisure industry largely consists of quick implementers and small
production series, thus offering quick payback and short term income, while the automotive
industry requires rigorous testing and verification of any component, thus resulting in longer
development phases and higher costs. However the up-side is that once a contract is awarded
and the supplying company has proved itself the contract runs over longer time periods and
the supplier’s technology or products may be implemented elsewhere in the vehicle as well,
specifically if weight and foremost cost can be reduced. Thus gaining a supplier relationship
with a large European automotive company can prove to be beneficial over the long term.
3.2 Volvo Cars’ perspective
The automotive industry is under constant pressure to reduce the weight of vehicles. Emission
restrictions such as the EU 2021 restriction, mentioned in chapter 2 being one main reason for
this. Another is the growing amount of electronics and batteries which are going in to new
vehicles today. As these components are quite heavy weight needs to be shed in all other
areas. This is mainly done through re-engineering of current components, using current
materials.
The need for weight reduction is forcing manufacturers to look to new materials. Lightweight
steel alloys such as magnesium and aluminum are already common in various components of
today’s vehicles, even plastics are widely used where load cases are acceptable. Recently
(read 10-15 years) manufacturers have begun to evaluate plastic composites as lighter
alternatives to various metallic materials. Since plastic composites differ quite a lot from
metallic materials the component needs to be fundamentally re-designed from the ground up
in order to benefit from the properties of the plastic composite material.
13. 7 | P a g e
4 Method
This project is a continuation of the work carried out in the product planning – needs and
opportunities course, which took place during the fall semester of 2014 (The project group,
2014). The group began by following up the opportunities which were identified. Two of the
opportunities, collaborating with Husqvarna or Thule were discarded early as no suitable
application was found. Two new opportunities did however arise after further brainstorming
with representatives from InXide; a high-end bicycle helmet and a lightweight pipe clamp for
the off-shore industry.
The three opportunities were evaluated through setting up business cases. The business cases
were designed according to the Real Win Worth-it framework (Ulrich & Eppinger, 2012),
which was chosen due to its simplicity and straightforwardness. The business case evaluation
proved that collaborating with Volvo Car Corporation and re-designing the load retention eye
was the most promising opportunity, both from InXide’s and the project group’s perspective.
To comply with the scope of the project the work was split into two Tracks, as seen in Figure
4. This way of structuring the work came as a request from Volvo Car Corporation, who
wished to see if the weight and cost of the current design could be lowered by integrating X-
TECH™ while not changing the design, as well as to see the full potential of what can be
achieved when working around X-TECH™. Therefore through consensus between Volvo Car
Corporation, InXide and the project group the work was organized into Track 1 and Track 2,
as described below.
Track 1: X-TECH™ is to be integrated into the current design in order to reduce weight and
cost, while keeping design changes to a minimum, in order to enable quick implementation.
Track 2: The group is to work around X-TECH™, with less constraints, thus demonstrating
the benefits of the material to a greater extent.
Opportunity Selection
(Load retention eye)
Track 1
Deliverables
Functional prototypes
CAD-models
Renderings
FEM-simulationsTrack 2
Figure 4: Illustrates the working structure of this project.
14. 8 | P a g e
4.1 Track 1
The approach used in Track 1 was based on the systems engineering approach as described by
Stevens (Stevens, 1998). The steps were slightly modified as to fit the design of the load
retention eye, as seen in Figure 5.
Figure 5: Illustrates the systems engineering approach used in Track 1 of this project.
System level requirements were identified through consultation with representatives from
Volvo Car Corporation and through reading the product specification as well as the ISO
27955 and DIN 75410-2 standards, which the component was to be tested according to. The
load retention eye was then structured into separate components, requirements were stated for
each component, in order to comply with the system level requirements. The components
were then designed and tested through an iterative process, by using CAD software to create
the design and to estimate the weights of the components. FEM software was used to verify
that the components withstood their respective load cases.
Once the group felt confident that the components were robust enough they were assembled,
ensuring that the components fit together. In this step CAD software was used to ensure that
the components fit properly. Once the components were integrated into a complete system,
prototypes were manufactured by outsourcing due to the complexity of the work. Two types
of prototypes were created, visual prototypes which were chrome plated in order to be as
similar to the current design as possible and purely functional prototypes which were to be
used for testing. These functional prototypes were used for testing in the system level testing
& verification phase. The prototypes were verified through tensile tests at Volvo Car
Corporation. These tests are described in detail in chapter 7, section 7.1.3. The system-level
testing & verification phase also included cost estimations for the redesigned load retention
eye, an LCA-analysis and an FMEA-analysis in order to compare the environmental impact
and the failure modes of the X-TECH™ redesign to the current design . The cost estimations
were split into internally manufactured components, outsourced components and assembly.
The internally manufactured components included, manufacturing of the X-TECH™ and the
injection molding of the components, the assembly costs were calculated using methods as
described by Swift (Swift, 2003). For the outsourced components the materials cost was
multiplied with a factor meant to cover labor cost and other expenses, in order to provide a
quick estimation.
The LCA analysis was carried using the EcoAudit software in CES EduPack, the parameters
measured where CO2-emissions and Energy Consumption. In order to compare the two
15. 9 | P a g e
designs, an LCA analysis was carried out for the current load retention eye as well as the X-
TECH™ redesign.
The FMEA has been carried out in the same manner as the LCA, conducting one FMEA for
the current design and one for the redesign, in order to compare the two.
The cost estimations were split into parts; internally manufactured components, outsourced
components and assembly. The cost of the internally manufactured components was estimated
by gathering information from InXide and KB Components. The cost of the outsourced
components was estimated in collaboration with InXide and the assembly cost was estimated
based on the methods of Swift (Swift, 2003).
4.2 Track 2
The workflow of Track 2 was structured according to the product development funnel as
described by Ulrich & Eppinger (Ulrich & Eppinger, 2012), Figure 6. Track 2 therefore
consisted of a concept generation phase, a concept selection phase and a detail design phase.
4.2.1 Concept generation
The concept generation phase followed the generic approach as described in Figure 7.
Beginning with Problem Clarification; the component was divided into three sub-systems, in
order to ease upcoming concept generation activities. The next two stages External Search
and Internal Search, were carried out in parallel as to fit the time plan of the project. The
external search included a competitor analysis, as to understand the competitors’ solutions,
expert consultation with representatives from both InXide and Volvo Car Corporation and
analyzing similar applications in other markets. The internal search revolved around
brainstorming sessions carried out using different stimuli. The stimuli was varied as to enable
the project group to explore large portions of the solution space. Stimuli used included sub-
systems, visual and functional mood boards, other areas of use identified during the external
search, and a change of environment.
The fourth stage Systematic Exploration was initiated by classifying the sub-solutions in a tree
diagram and eliminating unfeasible solutions in order to get a reasonable number of solutions
to work with. The remaining sub-solutions, to the three sub-systems, were then structured in a
morphological matrix and combined by selecting one solution from each sub-system. The
group members took turns choosing sub-solutions, a concept was then created for each
combination with the help of the other members. As a last step of the process the group
reflected over the approach used and the results, see Appendix A.
Concept
Generation
Concept Selection
Elimination 1
Elimination 2 Screen1
Screen 2
Scoring
Detail
Design
Deliverables
• 3D-printed
prototypes
• Visual Renderings
• CAD Models
Figure 6. The development funnel used in this project.
16. 10 | P a g e
4.2.2 Concept Selection
The concept selection phase, Figure 6, consisted of two elimination matrices, two screening
matrices and one scoring matrix. The initial elimination matrix consisted of basic criteria to
ensure that the concepts were feasible to carry out within this project, criteria included the
ability to work in tension and to fit the dimension constraints given by VCC. If each concept
fulfilled the criteria, or not, was judged subjectively by the group. After initial concept
refinement the concepts were inserted into the second elimination matrix, which included new
requirements. This matrix only included two criteria; stricter requirements on the ability to
work in tension and the possibility to attach loads using a hook, as further investigation
revealed this feature as a user requirement.
The concepts which passed the elimination stage were evaluated by using screening matrices.
The criteria used in the first screening matrix were divided into six main categories:
environmental requirements, safety requirements, aesthetics, performance requirements,
production requirements and ergonomics & user interaction. The concepts which score close
to the current design were improved and inserted in the second screening matrix, in order to
reassess possible performance improvements. In the second screening matrix the same
categories of criteria in order to make an equal comparison.
The final step of the concept selection phase was to select one or a few concepts to continue
working with, in order to do this a concept scoring matrix was used. The scorning matrix
offered a higher resolution as the criteria were weighted, a grading scale of 1-5 was used and
a reference concept for each criteria was chosen, instead of one reference concept for all
criteria. In the scoring matrix the criteria were refined, Appendix B definition of Kesselring
criteria, and in some cases combined as to be able to assign appropriate weights to each
criteria.
The concepts which were deemed most promising were further refined in the detail design
phase through the use of CAD software. The outcome was 3D printed prototypes and
renderings, in order to get a feeling for how the concepts might look.
In order to verify the concepts CAD models were used to assign materials to, which enabled
weight estimations. Visual renderings along with 3D printed prototypes were also produced in
order to better visualize the concepts and illustrate their functions.
Problem
Clarification
Decomposition
into sub-problems
External
Search
Competitor Analysis
Expert Consultation
Internal Search
Brainstorming
sessions
Systematic
Exploration
Tree diagram
Morphological
matrix
Reflection on
Results &
Process
Discussion
Reflection Report
Figure 7. Concept generation phase according to Ulrich & Eppinger (Ulrich & Eppinger, 2012).
17. 11 | P a g e
5 Opportunity Selection
This section will present the three opportunities, a short business case for each opportunity, of
which one was chosen for further development. During the opportunity identification phase in
the pre-project planning (The project group, 2014) the project group was in touch with
representatives from Husqvarna and Thule. Unfortunately both companies were forced to
withdraw their involvement, as no suitable application could be found within the given time
frame. The three remaining opportunities were then; cost and weight reduction of a
component for Volvo Car Corporation, development of a lightweight high-end bicycle helmet,
which at that time was without customer and a light-weight pipeline connection for the
offshore industry, also without a specified customer. This section further describes which
opportunity was chosen for the project, as well as a brief justification of the choice.
5.1 Business cases
Business cases were formulated for the three remaining opportunities, in order to compare
their potential with the same level of detail. The main limitation when assessing the
opportunities arose from varied knowledge concerning the different industries which the
opportunities were identified in. This added a dimension of uncertainty, meaning that an
opportunity might have been discarded mainly due to limited knowledge of the future
potential.
The business cases followed a defined model stated in chapter 4, beginning with a Project
description, which was divided into three parts: Background, Purpose and Guidelines. The
background description describes why the opportunity exists, followed by a section describing
the purpose of the opportunity. The third section included guidelines and consisted of any
constraints imposed on the opportunity, as well as the expected outcome. After the project
description the market potential was stated, under the heading Market. Here information
concerning the market potential of the opportunity was described, with simple estimations of
potential sales volumes. The next section stated the financials of the opportunity, where
estimated sales volumes and estimated unit price was combined in order to determine payback
time and profit of the opportunity. The last two headings were Benefits and Disadvantages,
which both are self-explanatory, Appendix C.
5.1.1 Lightweight, high-end bicycle helmet
The first opportunity came from the sports industry and was a result of a dialogue with
InXide; it consisted of a lightweight continuous fiber reinforced bicycle helmet. The purpose
of integrating an X-TECH™ reinforcement into a bicycle helmet was to reduce the crack
propagation between beads of the foam which the helmet is made up of, thus enhancing the
impact resistance of the helmet and making it re-usable after an impact. As the price of
integrating a continuous fiber skeleton into a bicycle helmet would be high compared to
conventional helmets the targeted market segments was identified as; enthusiasts who demand
high performing equipment as well as professional cyclists. The main feature of a bike helmet
where X-TECHTM
is utilized would be lower weight, due to the possibility of using a lower
density foam when held together by the X-TECHTM
reinforcement. The estimated customer
price for a high-end helmet, when analyzing the current supply, would be in the range of
1500-2000 SEK. This would allow a higher profit margin compared to working in the
automotive industry (after deductions for retailers and other actors in the supply chain). The
sports equipment industry does however seem to offer fierce competition without the benefit
of a long term contract, as interpreted from talking to representatives from InXide who have
experience from this industry. For further information concerning this business opportunity,
see Appendix C.
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5.1.2 Pipeline connection for offshore usage
The second business opportunity was found by InXide when visiting the JEC 2014 industry
fair in Paris (JEC Group, 2015). The idea was to manufacture piping clamps for offshore use
when laying temporary pipelines. The main benefit of the clamp was the weight reduction,
which would enable easier handling when installed and removed by divers. The clamp would
be manufactured in a range of sizes, matching standardized pipe dimensions in use today. The
margin for profit was deemed as high but the market was unclear and involved high risk. The
main risk identified was the impact of one single failure, which might result in oil leaks and a
natural disaster, thus damaging the reputation of a small company like InXide severely. For
further information about this business case, see Appendix C.
5.1.3 Load retention eye in the all new Volvo XC90
The third business case was identified in the pre-project planning phase. The project involved
weight and cost reduction of a component in Volvo Car Corporation’s all new XC90 model.
More specifically, this component would be a load retention eye, of which four are mounted
in the trunk of the vehicle. The two objectives of the opportunity would be to lower the
weight as well as the cost of the load retention eye. The business case for this opportunity
offers the lowest profit margin, but is well defined by market size and projected annual sales
volumes, it also has a specific customer, Volvo Car Corporation. For more information about
this business case, see Appendix C. The load retention eye will below be referred to as a
product, since it consists of multiple parts.
5.2 Selecting opportunity
The Business cases were, as mentioned in chapter 4, evaluated using the RWW-framework.
The conclusion was to eliminate the pipe clamp. This due to the fact that no customers had
been identified, the market was unclear and the risk deemed as too high. Thus the bicycle
helmet and the load retention eye were both kept for concept generation. The bicycle helmet
opportunity was kept as InXide would attempt to identify a customer at an upcoming industry
fair in Munich. It was however eliminated later as no customer was identified. Also a patent
was found, which the product would infringe on. This left the opportunity of the load
retention eye in the Volvo XC90 for further development.
5.3 Verification of application
In order to ensure that the load retention eye was a suitable application the group took a step
back and assessed other possible applications within the XC90. This was done through a
brainstorming session where other possible applications in the vehicle were identified. For
applications identified and the scoring of each compared to the load retention eye. This
session resulted in two other promising applications; the inner roof handle-bar and the towing
hook. Both carry tension loads suitable for X-TECHTM
. However, the inner roof handle-bar
appeared to be an application which was not in need of weight reduction, while the towing
hook did not provide any potential for cost savings. Thus, these applications were eliminated
and the load retention eye was accordingly justified to be a promising demonstrator
application for X-TECH™ and the scope of the project. Furthermore, the application of the
load retention eye was identified as having a potential for both weight and cost reductions by
employees at Volvo Cars.
19. 13 | P a g e
5.4 Description of demonstrator application
This chapter aims to briefly describe the functionality and features of the demonstrator
application; the load retention eye fitted in the trunk of the Volvo XC90, shown in Figure 8.
The main components of the product are the housing and the tongue, component 1 and 2 in
Figure 9. The tongue is mounted to the housing by a steel pin (3) between which the friction
elements (4) are fitted. Component 5 is a thin, bended metal plate, which minimizes the gap in
vertical direction between the housing and the side panel in the interior of the car. The load
retention eye is attached to the side panel in the car with a screw and a washer through the
hole in the housing. The tongue can be folded out, rotating around the pin, and a cargo net or
a similar cargo-securing accessory can be attached by using a hook. Figure 9 demonstrates the
basic appearance of the load retention eye and the included parts.
Figure 8. Illustrates the trunk of the Volvo XC90. The red arrows point out approximately where
the LREs are fitted. The picture is retrieved from
http://www.caricos.com/cars/v/volvo/2015_volvo_xc90/1920x1080/60.html [2015-05-29].
20. 14 | P a g e
When a hook is attached and tensile loads are applied in line with the tongue, tension stresses
occur in the tongue. The loads are then transferred through the pin to the housing, which
further transfers the loads through the screw and the washer to the car chassis, to which the
product is assembled. The highest stresses are then located in the tongue at the thinnest cross
sectional areas on both sides of the hole. Figure 10 illustrates where the tensile stresses occur
in the tongue when a hook is attached and a tension load is applied.
The current tongue and housing is a molded Zink alloy component. The surface of the tongue
is chromed and the housing has a powder-coated surface with a color shade specified by VCC
in order to match the interior color scheme variants offered for the XC90. The pin is made
from a hardened steel alloy, and the friction elements are made of a polypropylene polymer.
The thin bended steel plate is manufactured from an unknown steel grade, as the mechanical
properties are not critical for the functionality of the load retention eye. The weight of the
Figure 9. Illustrates the current design in folded-in position (to the left), and an exploded view visualizing the included
components (to the right). The included are numbered: Housing (1), Tongue (2), steel pin (3), friction elements (4) and the
thin bended metal plate (5).
Figure 10. Illustrates the current design in a folded out position. The red circles (to the left) mark where in the tongue the
tensions stresses occur when a hook is attached and a tension load is applied in line with the tongue, as illustrated by the
red arrow (to the right).
21. 15 | P a g e
product is 308 grams per unit, according to VCC. Further information about the materials and
the environmental impact of the product is found in chapter 7, section 7.1.3.
The product is part of the passive safety system of the vehicle. In development projects at
VCC each system is usually given a specified maximum weight. This means that the weight
of a sub-system component limits the weight of other components in the system. Thus,
reducing the weight of the load retention eye could have two consequences; lowering the
overall weight of the vehicle reducing fuel consumption, or allowing other features to be
added to the passive safety system without exceeding the maximum weight of the system.
Hence the weight of the load retention eye is a limitation for either reducing fuel consumption
or including additional features to the passive safety system.
The current cost of the product is relatively high. Using the projected sales volumes and the
current detail price, provided by VCC, the product will have an annual cost of approximately
10,200,000 SEK. If the product would be carried over to additional car models, the annual
cost would increase. Thus, the annual savings with an X-TECHTM
re-design would also
increase. The application therefore provides promising opportunities for weight and cost
reduction. This, along with the load case in the tongue makes the application suitable for
demonstrating X-TECHTM
.
22. 16 | P a g e
6 Product Concept
This chapter describes the concept design phases of both Tracks. For Track 1 this includes a
concept description, system level requirements, and break down into sub-systems including
the assigning of requirements to each sub-system. For Track 2 this includes requirement
identification, concept generation and concept selection.
6.1 Track 1
This section describes how Track 1 was carried out and what the result from each step was.
As mentioned in chapter 4 a systems engineering approach was used for the development
efforts (Stevens, 1998). The steps were modified in order to fit the product in question, the
load retention eye of the all new Volvo XC90, these steps are illustrated in Figure 5 in chapter
4.
6.1.1 Concept Description
As mentioned in section 5.4, the function of the load retention eye is to secure cargo such as
luggage or a cargo net. In order to do this, three critical areas of load transfer were identified.
The first was from the attached cargo through tongue, the second from the tongue to the
housing and the third through the housing and into the chassis of the vehicle. In the current
solution the load is transferred from the attached cargo through the tongue by the molded zinc
tongue itself. The group concluded that weight could be saved by replacing the material of the
tongue with an X-TECH™ reinforced plastic, as seen in Figure 11. The second load transfer,
from the tongue to the housing, was done by the hardened steel pin which connects the two
components, in order to reduce weight of the material would have to be replaced or the
connection would have to be completely redesigned, which stands in contradiction to the
visual requirements. The third transfer point, through the housing and into the chassis, is
currently done by the zinc material in the housing and a steel screw and washer. The group
did not feel the screw and washer needed replacing. However, as the housing was also made
from zinc this component also showed great potential for weight reduction. The issue with the
housing would be to develop a design which could transfer the moment from the tongue to the
chassis, as seen in Figure 11, while weighing less. This had to be done without changing the
dimensions of the component.
23. 17 | P a g e
6.1.2 Load Retention Eye Requirements
The team began by identifying requirements, both qualitative and quantitative, for the load
retention eye, this was done through consultation with representatives from Volvo Car
Corporation, analysis of the product specification of the current design and through studying
the ISO 27955 and DIN 75410-2 standards, which the prototypes were to be tested according
to. Through discussions with the representatives from Volvo Car Corporation it was found
that, even though the chroming was quite costly it was a requirement which could not be
compromised on. It was also discovered that according to the DIN 75410-2 standard a circular
space with Ø 20 mm was required if the car was to be sold on the German market without
supplying custom load loops for load attachment, thus the Ø 20 mm circular area was made a
requirement. The ISO 27955 and DIN 75410-2 standards included three tension tests, which
are described further in chapter 7, section 7.1.3, other requirements included, among others,
“same or lower environmental impact as current solution” and “give a quality impression”.
The full requirements list is found in Appendix D. The group expected the requirement of
20% cost reduction to be tricky to fulfil, since at the time the requirement was stated little was
known about how the product would be redesigned and what solutions were to be
implemented, this proved to be wrong as the requirement was fulfilled. Another requirement
which was deemed difficult to comply with was the cost of chrome, this requirement was not
met, although the overall cost reduction of minimum 20 % was, which makes one wonder if
the requirement fulfills any function.
6.1.3 Component Breakdown & Component requirements
Once the product requirements were identified, the load retention eye was divided into sub-
systems, this resulted in the following three components: The Pin, The Tongue and The
Housing. Each requirement was allocated the appropriate component, in some cases the same
requirement was allocated to more than one component, Appendix D. For instance, the
requirement of a chromed surface was allocated to the tongue, while the requirement to
withstand 4.38 kN for 30 seconds without any separations was assigned to all three of the
components. The requirements regarding the appearance of the load retention eye were of
great importance, as the whole idea of Track 1 was to implement X-TECH™ while
complying with the current design.
d
F
M = F * d
Figure 11: Illustrates the proposed layout of the X-TECH™ reinforcement (to the left), and the moment which must be
transferred through the load retention eye and into the chassis (to the right).
24. 18 | P a g e
6.2 Track 2
This section describes the process for the development efforts carried out in Track 2, which
aimed at developing innovative concepts demonstrating the future design possibilities when
designing around X-TECHTM
. To guide these efforts, the framework for design and product
development presented by Ulrich & Eppinger (2012) was used.
6.2.1 Requirement Specification
The requirements that were to be used during the selection of the generated concepts were the
same as the requirements for the Track 1 with some additions. These additions were made
since the focus for Track 2 was not only to replace the material but also to come up with new
design solutions. The additional requirements were identified both by dialogues with
representatives from VCC and InXide but also through brainstorming sessions conducted
within the project group. The requirements identified were expressed as customer needs, for
example should cost less than the current solution. In order for these customer needs to be
used in the concept selection, they had to be reformulated into engineering requirements, for
example cost estimations were reformulated as; cost less than XX SEK or XX % cost
reduction, compared to the current solution. For the full requirements list see Appendix E. All
requirements are categorized into five categories; Financial Aspects, Technical Performance,
Environment & Lifecycle, Ergonomics & User Interaction, and Educational perspective.
6.2.2 Concept Generation
The five-step concept generation method, proposed by Ulrich & Eppinger (2012) was used as
a guideline when planning the concept generation phase. In the early activities the theory was
closely followed but as the work progressed the group began to adapt the tools to better fit this
specific project. This chapter describes the concept generation phase and its constituents. As a
result fifty concepts were generated, the results are presented in Appendix F. Before the
concept generation phase was finalized all concepts were refined to the same level of detail.
In section 6.2.2.5 four of the fifty concepts, generated during this phase, are presented.
6.2.2.1 Problem Clarification
To get a general understanding of the problem the functionality of the load retention eye was
broken down into sub-functions. After a thorough examination the sub-functions illustrated in
Figure 12 were identified.
25. 19 | P a g e
Figure 12. Function Tree over the innovative future solution.
Out of the eight sub-functions, three were identified as key sub-functions necessary for the
overall functionality of the load retention eye; Attachment of cargo, User interaction and
Assembly design.
One basic requirement, most important to fulfill, is to transfer energy from the accelerating
cargo to the chassis of the vehicle. If the load retention eye would not secure the cargo, it
loses its main function. The consequences of this could be that the cargo injures the driver or
passengers, as well as damaging itself and the car during acceleration or retardation.
Therefore, the sub-function attachment of cargo is a critical sub-function. One challenge with
this function is to design the component so that the load case mainly acts in tension, in order
to utilize the properties of X-TECH™. Another challenge, with this application, is to fit the
X-TECH™ reinforcement in the component, without jeopardizing the strength and the surface
quality of the load retention eye.
For the user to be able to secure cargo, the user interaction with the load retention eye, must
be evaluated. The user interaction is a big part of how the user perceives the load retention
eye as a product. Failing to satisfy the user would thus lower the overall quality impression of
the vehicle. Hence, user interaction was identified as one of the sub-functions with the
greatest impact on the product. A challenge was balancing the trade-off between innovation,
intuitiveness, simplicity, and safety. Another challenge was keeping the number of parts
down, as to ease manufacturing and lower assembly costs.
As the third and final sub-function, assembly design was identified. This sub-function
involves how the components of the load retention eye are connected to each other and how
the load is transferred through the load retention eye and into the chassis of the vehicle. If the
load transfer is not successful, the function of the load retention eye is lost. One difficulty was
finding an interface which both transferred the load in an efficient manner while connecting
the components.
Secure Cargo
Assembly design
Internal Parts
Connect to
chassis
Connect Cargo
User
Interractaction
Attachment of
cargo
Product Design
Active Design Passive Design
Secure Passive
Design
Transfer/Absorb
Energy
X-tech
26. 20 | P a g e
6.2.2.2 External Search
Functional benchmarking sessions where conducted where the group looked into other
industries to find applications with similar functions. This research was an effective way to
start a thought process and gain inspiration of how some of the sub-functions could work. One
industry which was investigated closely was the vehicle accessories industry. Analyzed
products included; bike racks, trailer hooks, straps for securing cargo and roof rails. Other
investigated products included; excenter locks, hand cloves, belt lock systems and disk
brakes.
During the concept generation phase, meetings were conducted with representatives from
both InXide and Volvo Car Corporation. In these meetings the project group discussed
possible sub-solutions, production, visual design and assembly processes. A site visit was also
carried out, at KB Components site in Örkelljunga, Sweden, where InXide’s production cell is
located. During this visit the group gained knowledge about the pultrusion process and the
injection molding process.
In addition to the functional benchmarking sessions, expert consultations and the site visit, the
project group participated in a concept generation workshop involving other M.Sc. students at
Chalmers University of Technology, who worked with similar projects in other industries.
The purpose of the workshop was to stimulate discussions and generate new ideas of possible
concepts. The workshop generated feedback and new inputs from individuals who had
different perspectives as they were not involved in this project.
The outcome of the external search is intangible as it consisted of gained knowledge
concerning the manufacturing process and inspiration of how to approach and solve the three
sub-functions.
6.2.2.3 Internal Search
During the concept generation phase multiple brainstorming sessions were carried out, using
different kinds of stimuli. One kind of stimuli used was mood boards (Ulrich & Eppinger,
2012). Each group member created their own mood board consisting of pictures, which each
group member associated with the load retention eye. During the sessions, the project group
had thorough discussions on why and how each group member associated the pictures to the
load retention eye. These brainstorming sessions were not that productive in generating sub-
solution. However, the group member gained understanding of what and how the others
prioritized attributes. With this knowledge, the project group could create a common mindset.
For one set of brainstorming sessions the project group used a completely different kind of
stimuli, a switch of environment. The sessions were conducted in a different and more
relaxing environment than the regular working environment. Together with the new
environment, the project group also used bits of information collected during the external
search as a base for the sessions. Due to the relaxed nature of the sessions focus varied
between sub-solutions and generating product concepts, thus only few sub-solutions was
generated. However, 31 product concepts were generated, among these were the slot and the
logo, see Appendix F. Thus the brainstorming sessions were regarded as productive. The
reason for the high productivity could be that stress and pressure associated with working at
campus did not influence the group, thus the brainstorming sessions were experienced more
as a “fun” event.
The project group also conducted a set of more conventional brainstorming sessions, without
any stimuli. These sessions focused on generating solutions to the sub-functions, found in
Table 1. To encourage wild ideas and exploration of the entire solution space, no idea was
27. 21 | P a g e
regarded as a bad idea. In later stages the outcome of these brainstorming sessions would be
the base for the morphological matrix.
6.2.2.4 Systematic Exploration
During the external and internal searches, a large number of sub-function solutions were
generated. In order to cope with the amount of solutions the project group structured the sub-
functions in a function-means tree diagram. The solutions, which were considered unfeasible
were removed. Such solutions included, welding the cargo to the load retention eye. After
screening, nine to twelve solutions remained for each sub-function.
The remaining sub-solutions were inserted into a morphological matrix, see Appendix G.
Considering all possible combinations, in theory, 1188 concepts could be generated.
However, in reality some sub-solutions were dependent, on being combined with sub-
solutions of a different function, in order to be feasible. Thus in reality the number of possible
combinations was less than 1188. The group generated complete product concepts by
selecting one sub-solution from each of the three main functions. The choices were based on
the knowledge gained from the external and internal search, and not by exhausting
combination of sub-solutions as might be preferred (Ulrich & Eppinger, 2012). Hence, the
number of generated product concepts was low, however all concepts were feasible to some
extent. In total, 16 concepts were generated through the morphological matrix. When looking
back and reflecting on the process the project group realized that this approach might not have
utilized the morphological matrix efficiently. This issue is further discussed in Appendix B.
6.2.2.5 Generated Concepts
Throughout the concept generation phase a total of fifty concepts were generated, which can
be found in Appendix F. The external search did not result in any finished product concepts.
This phase was instead used to explore competition and other areas of use, to gain inspiration
and knowledge for the internal search and the systematic exploration phase. The internal
Assembly Design User interraction Attachement of cargo
Glueing Push Hooking
Pinning Pull Screwing
Soldering fold Magnetism
Hinge Touch Sucking
Friction Suck Looping
Chemical adhesion Sound "Velcroing"
Magnetism Sensor Zipping
Heat expansion Scroll Bottoning
Screwing Open/close trunk Create under-pressure
Snapping in place Chellphone Key-hole
90degree plate lock Instrument panel 90 plate lock
No fastening From driver seat Glue
Using Sprints Steering wheel Soldering
Car key Welding
Turn Friction
Fingerprint Knot
Heat expansions
"Snap in"
Table 1. The three sub-functions identified and their respective solutions.
28. 22 | P a g e
search resulted in a total of 34 concepts, of which three came from the mood boards and the
remaining 31 from the brainstorming sessions in a relaxed environment, with the functional
benchmarking as inspiration. Apart from the large number of concepts the internal search also
produced the sub-solutions, which were inserted in the morphological matrix during the
systematic exploration phase. The morphological matrix resulted in sixteen product concepts.
Due to the fact that concept generation took place at different dates and under different
circumstances, the level of detail of the documentation has varied. Thus before concluding the
concept generation phase it was ensured that all concepts had the same level of
documentation, in order to enable unbiased judgment in the concept selection phase. The
documentation of all concepts included; a name, a rough sketch, a description of function, as
well as pros and cons. In the four following sub-sections are four of the fifty concepts
presented. They include the concepts that made it far through the concept selection phase and
preceded to the concept scoring. Pictures of the initial sketches of these four concepts are
shown in Figure 13.
6.2.2.5.1 The Bar
The Bar is a static solution with a bar at the center, to which a hook can be attached. Pros;
Minimize material utilization, Simple, Robust. Cons; not innovative, requires depth to be
mounted, complex to connect to chassis with one screw.
6.2.2.5.2 The Logo
The concept illustrates the logo of Volvo Car Corporation. A pin runs through the middle of
the component, the lower half circle of the concept is attached to the pin and can thus be
folded out, for loads to be attached. It is in this lower half circle the X-TECH™ reinforcement
is integrated Pros; eye catching, robust, innovative. Cons; requires an assembly process, may
need different colors to distinguish and requires depth when mounted to chassis.
6.2.2.5.3 The Slider
The slider uses a buckle, which slides in and out of the housing that stores the buckle when
not in use. Cargo is attached to the buckle, when in the folded out position, using a hook or a
load loop. Pros; does not require much depth, innovative, intuitive. Cons; contains many
parts and requires moving mechanism.
6.2.2.5.4 The Strap
A cylinder is pulled out of the side-panel. Cargo is attached to the cylinder by a hook or load
loop, when not in use the cylinder is stowed in the side-panel thus only a chromed half circle
surface is visible. Pros; flexible, requires little space, simple. Cons; can be hard to
demonstrate with X-tech (in reasonable dimensions) and can be hard to retract.
Figure 13. The first generation of sketches, from the left; The Bar, The Logo, The Strap and The Slider.
29. 23 | P a g e
6.2.3 Concept Selection
In this phase the concepts that were generated during the concept generation phase were
evaluated and reduced from fifty to two. This was done with respect to the previously
identified customer needs, and other criteria described in Appendix E, by utilizing the concept
selection method presented by Ulrich and Eppinger (2012). The selection process described in
this chapter, was modified to fit the project and was carried out in five steps using five
matrices; two elimination matrices, two screening matrices and one scoring matrix.
6.2.3.1 Concept Elimination 1
In the first Elimination, see excerption in Figure 14 the concepts had to pass all the criteria in
the matrix in order to advance to the next matrix. One part of the criteria used in this matrix
was dimension criteria which had to be fulfilled for the part to fit in the car. These criteria
were the same dimension criteria as VCC had on the current load retention eye, since the
generated concepts should be able to replace the current solution. The other part of the criteria
used were criteria, which the group identified as critical to the success of the project. These
criteria were generated through brainstorming followed by multi-voting (Ulrich & Eppinger,
2012) where the most important criteria were chosen.
As Figure 14 shows, Cool Velcro and MagHingeNet were eliminated due to not being able to
carry tension loads, which is one of the main criteria for the solution to be suitable for
utilizing the properties of X-TECHTM
.
The elimination was carried out by evaluating each concept towards the same criteria before
moving to the next one in order to keep the same mindset for all the concepts. The concepts
were given a green mark if it passed the criteria and a red mark if did not. When a concept had
received a red mark it was eliminated and no further evaluation of that concept was
performed.
During the evaluation of the concepts it was found that some of the concepts were not
described well enough to do an equal evaluation towards each criteria. Therefore some
concepts were given a yellow mark which meant that it was uncertain if the concept fulfilled
the criteria or not. When all the concepts had been evaluated, the concepts that received one
or more yellow marks were more thoroughly examined before they were either eliminated or
moved to the next matrix.
The elimination resulted in a reduction from fifty to twenty concepts. Since there was a lack
of description of the concepts during the elimination, these twenty concepts were updated
with more detailed sketches to enable a more thorough evaluation.
To be able to evaluate all concepts equally against the elimination criteria, it was identified
that twenty concepts would be too extensive to comprehend. Therefore the group decided to
perform another elimination matrix to reduce the number of concepts before proceeding to the
screening.
30. 24 | P a g e
6.2.3.2 Concept Elimination 2
The second screening matrix consisted of only two criteria; Carry mainly tension loads and
Loads can be attached using a hook, Appendix H. The criterion Carry mainly tension loads
which was used in the first elimination matrix was believed to be too vague and that many
concepts could carry tension loads, to some extent, without being able to utilize the properties
of X-TECHTM
. Hence, this criteria was formulated clearer and the concepts were evaluated in
a more criticizing manner in the second matrix. The requirement Loads can be attached using
a hook was part of a DIN standard, which applies to this application, and was therefore
included in the second elimination matrix. Another difference compared to the first
elimination was that the concepts were only marked with either pass or fail, red or green
markings. The second elimination matrix resulted in the elimination of another ten concepts.
This step was ended by illustrating all concepts which passed the elimination phase with the
same level of detail. This was done through 3D sketches, see Appendix I refined concepts.
6.2.3.3 Concept Screening 1
A Concept screening matrix was set up, the concepts were inserted and evaluated against the
criteria shown in Figure 15. The current design was used as a reference for each criteria. All
the concepts were evaluated against one criterion before moving on to the next criterion. This
was done in order to keep the same mind-set for all the concepts.
The criteria used in the matrix were divided into six categories; environmental criteria, safety
criteria, aesthetics, performance criteria, production criteria and ergonomics & user
interaction criteria, Figure 15. This categorization was performed in order to cover needs
from different areas to ensure that all important stakeholders’ needs were included. The
concepts were ranked using a scale including “-“, “0” and “+”, where the reference concept
was scored with “0” for each criterion. The total score of a concept was thus decided by
subtraction the numbers of “-” from the number of “+” the concept received.
As Figure 15 shows, The Logo and The Bar received the highest score and therefore advanced
to the next matrix. The Figure also shows that The Strap had the same rank as The Logo,
however during the screening process improvements were identified. However after
investigating the matter with InXide the concept was deemed unfeasible, as implementation of
X-TECH™ proved more complicated than anticipated. It was therefore eliminated. The
concepts that are marked with yellow in Figure 15 were concepts which the group believed
Concepts
Carrytensionloads
Estimatedcost/unit<€XX
FitprojectbudgetFitprojecttimeplan
Estimatedweightreductionby20%
Maximumthickness;19.4mm
Maximuminsertthickness;14.5mm
GO/NO-GO
Intressting
Button down Yes
Cool Velcro No
MagHingeNet No
MagnetHole Yes
Non Touch Flag Pole No
Pushing key hole Yes
S.T.a.N. No
Scrook Yes
The fisherman Yes
The grower Yes
The Hidden Screw Yes
The turner No
Touching Lock No
Turking No
Were screwed No
Whistle sucker No
The trap door No
The Key Hole No
The Folder No
Electro No
Ball Lock No
Cigearette Botton Yes
Collapse Hok Yes
Drill Cone No
Removable friction No
Ski-strap Yes
Snap Yes
The angled hook No
The arrow Yes
The Bar Yes
The boat hook Yes
The bridge Yes
The Claw Yes
The cross Yes
The door handle No
The double No
The logo No
The slider Yes
The squeezer No
The stick No
The strap Yes
The sumo hook No
The trailer hook No
The trap No
The Cliffhanger No
The Key to heaven No
The Slot No
The Victor No
The wall-hook Yes
Trailer strap No
MorphologicalMatrixMood
BoardFunctionalBenchmarking
Figure 14. Criteria for concept elimination 1, see Appendix H for the full matrix.
31. 25 | P a g e
could be improved through minor changes and thus advance to the next matrix. The
improvements were made through brainstorming sessions, changes which improved
performance without altering the overall design of the concept were done. The three concepts
marked with red in Figure 15 were eliminated, as they were considered to perform worse than
the current design in several areas.
6.2.3.4 Concept Screening 2
The second screening was performed with the concepts which were improved after the
previous screening, together with two new concepts Cpt. Haddock and The Banana. Cpt.
Haddock was the result of improving The Boat Hook, while The Banana was a new concept,
which derived from The Boat Hook as well. The concepts were evaluated following the same
procedure, using the same criteria as the first screening in order to verify if concept
performance had been improved.
The two concepts Magnet Hole and Color Five were eliminated from further development
even though they performed better than The Slider, according to the ranking, which was to be
improved. The reason for this was that after each matrix had been carried out, the group
discussed if the result of the ranking conformed to the perceived potential of the concept. The
ranking in the screening matrices was used as an indication of which concepts to further
develop, rather than as a fact. Hence the ranking of the concepts did not always dictate which
concepts were to be further developed.
CurrentsolutionMagentHoleTheSchrook
TheLogoTheCollapsableHookColor5
TheCross
TheBarTheBoatHookTheSliderTheStrap
Separability of materials used 0 - - - - - - - - - -
Recyclability of materials used 0 - - - - - - - - - -
No injuries from direct interaction 0 0 0 + - 0 0 + + - +
Presents no risk for third row passengers, when passive 0 0 - + - 0 0 + - + +
Gives a visual impression of quality 0 0 - 0 - + - + 0 0 +
Gives a physical imression of quality 0 0 - + - 0 - + - 0 +
Adapable to communicate VCCs design philosphy 0 0 - + - + - 0 - 0 0
Pass technical tests, acc.ISO & DIN std. 0 0 0 + - 0 - + + 0 0
Free space for load fastening; min 20mm 0 0 0 0 + 0 - 0 0 0 0
Utilize X-tech 0 0 + + - 0 + + + 0 +
Keep the skeleton in tension during manuf.process 0 0 0 + + 0 - + + + +
Producability using X-tech 0 - - + - 0 - + + - +
Keep thickness transitions to a minimum 0 0 - 0 + 0 + + - 0 +
Ease of fastening load, using one hand 0 0 0 + 0 0 0 + + - +
Self-evident to use 0 0 0 + - - - + - - +
Number of "+" 0 0 1 10 3 2 2 11 6 2 10
Number of "0" 15 12 6 3 1 10 3 2 2 7 3
Number of "-" 0 3 8 2 11 3 10 2 7 6 2
Score 0 -3 -7 8 -8 -1 -8 9 -1 -4 8
Rank 4 7 9 2 10 5 10 1 5 8 2
Comments
Improve
Improve
Improve
Improve
Improve
Environmental
Ergonomics &
User Interaction
Production
Performance
Aesthetics
Safety
Figure 15. Concept screening 1.
32. 26 | P a g e
6.2.3.5 Concept Scoring
As the concepts through to this stage fulfilled the basic criteria, such as outer dimension
requirements and utilization of X-TECH™. The concepts also passed through the screening
matrices which indicated that they complied with customer needs related to environmental
aspects, safety, aesthetics, technical performance, production, and user interaction &
ergonomics. This implies that all concepts would probably be suitable for implementation.
Therefore the criteria for the scoring matrix, see Figure 17, were chosen to find the best
concept(s) rather than eliminating the worst.
In order to be able to assign reasonable weightings to each criterion the criteria of the
screening matrices were combined where possible, while new needs were added as well. One
example of criterion which were combined were the visual and physical quality impressions,
which were combined into gives quality impression. One criterion which was added was ease
of assembly. Before each criterion was assigned a weight the group wrote down a common
definition of what each criterion included, Appendix B.
The weighting of the criteria, see Figure 17, began with discussing each criterion and its
relative importance to the product. Each criterion was given an initial weight without having
the sum of the criteria in mind, thus the total exceeded 100 %. The final weightings of the
criterion were determined through multi voting, if each criterion was to be given a higher or
lower weight than the initially set. To finalize the weightings the group summed up all the
different criteria’s weights and made corrections so that the total sum was 100 %.
When evaluating the concepts the group identified a concept with average performance for
each criterion (marked with yellow in Figure 17). The concept which scored average for a
specific criterion was used as a reference which the remaining concepts were evaluated
against.
CurrentsolutionMagentHole
Color5
TheBanana
TheSliderCpt.Haddok
Separability of materials used 0 - - - - -
Recyclability of materials used 0 - - - - -
No injuries from direct interaction 0 0 0 + - +
Presents no risk for third row passengers 0 0 0 0 + -
Gives a visual impression of quality 0 0 + + 0 +
Gives a physical imression of quality 0 0 0 0 0 0
Adapable to communicate VCCs design philosphy 0 0 + - 0 -
Pass technical tests, acc.to spec. 0 0 0 + 0 +
Free space for load fastening; min 20mm 0 0 0 + 0 0
Utilize X-tech 0 0 0 + 0 +
Keep the skeleton in tension during manuf.process 0 0 0 + + +
Producability using X-tech 0 - 0 + - +
Keep thickness transitions to a minimum 0 0 0 + 0 -
Ease of fastening load, using one hand 0 0 0 + - +
Self-evident to use 0 0 - 0 - -
Number of "+" 0 0 2 9 2 7
Number of "0" 15 12 10 3 7 2
Number of "-" 0 3 3 3 6 6
Score 0 -3 -1 6 -4 1
Rank 4 3 1 5 2
Comments
Improve
Improve
Ergonomics &
User Interaction
Environmental
Safety
Aesthetics
Performance
Production
Figure 16. Concept screening 2.
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The result from the scoring process showed that two concepts performed better than the rest,
The Logo and The Bar, for almost all criteria. These two concepts showed high potential for
cost and weight reduction, while giving the highest quality impressions. The final score of the
two concepts were similar, which led the group using both as final concepts. Both concepts
would therefore be presented for VCC with different selling points. For the representatives
from VCC to be able to evaluate the visual design of two concepts more thoroughly 3D-
printed models were produced.
Selection Criteria Weight Rating
Weighted
Score
Rating
Weighted
Score
Rating
Weighted
Score
Rating
Weighted
Score
Rating
Weighted
Score
Rating
Weighted
Score
Quality Impression 19% 4 0,76 5 0,95 3 0,57 2 0,38 3 0,57 2 0,38
Cost reduction from XX SEK 19% 5 0,95 5 0,95 3 0,57 1 0,19 2 0,38 2 0,38
Usability 10% 4 0,4 5 0,5 3 0,3 2 0,2 5 0,5 5 0,5
Ease of assembly 11% 3 0,33 3 0,33 5 0,55 2 0,22 4 0,44 4 0,44
Producability using X-Tech 18% 5 0,9 5 0,9 3 0,54 2 0,36 4 0,72 2 0,36
Demonstrate X-tech 23% 3 0,69 3 0,69 4 0,92 1 0,23 5 1,15 2 0,46
Total score
Rank
Proceed?
Cpt Haddok
4,03 4,32 3,45 1,58 3,76
The Logo The Bar The Banana The Slider The Strap
Rating 1-5
Yellow is reference (3)
No
2 1 4 6 3 5
Yes Yes Maybe No Maybe
2,52
Figure 17. The Concept Scoring matrix.
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7 Detail Design & Prototyping
This chapter includes the detail design phase, testing and verification of prototypes. As Track
1 was to be ready for quick implementation the efforts were put on producing prototypes and
verifying this design. As Track 2 is for future inspiration and due to the time frame of the
project this Track could not be evaluated to the same extent.
7.1 Track 1
The detail design and evaluation of prototypes followed the systems engineering approach,
described in chapter 4. The work carried out is described in this section. The final verification
includes testing of technical, economic and environmental performance.
7.1.1 Component Design & Component Testing
Each component was designed and verified separately in this stage.
7.1.1.1 Pin
The design of the pin remained the same as this component was of a simple nature and the
group concluded that no changes had to be made. For the prototypes a different kind of steel
was used due to greater availability, the work done on the pin revolved around ensuring that
the component would withstand the load cases of the tension tests. In order to verify this
FEM-analysis were carried out, further described in coming sections (section about housing
and tongue).
7.1.1.2 Housing
The group concluded that the housing would not pass the tension tests if replaced straight off
with an unfilled polyurethane (PUR) material. Therefore it had to be reinforced in some way.
In order to Figure out how, brainstorming sessions were conducted. The identified
possibilities were to use X-TECH™ in some way, a metallic plate or InXide’s X-SHELL™
technology (InXide, 2014). The use of X-TECH™ in the housing was soon abandoned as it
seemed quite unfeasible because of the moment created in the housing during loading.
Discussions were held within the group and with representatives from InXide in order to
decide which of the two remaining choices seemed the most suitable, thereafter the pros and
cons for each option where compared. The final verdict was that a steel plate would be the
best solution, when taking cost, manufacturability and quick implementation into account.
Although using X-SHELL™ might have proved a better demonstrator of InXide’s
technologies the three previously mentioned factors outweighed this one. The steel plate was
designed as illustrated in Figure 18, where the bended sides not only fixate the pin and
transfer the load into the chassis of the car, but also act as stiffening ribs.
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Figure 18: A rendered picture illustrating the design of the steel plate.
For the Track 1 design features designed to ease assembly, to the chassis of the vehicle, were
modified as well. The two features used for assembly are the features at the bottom of the
component and the thin steel plate at the top, illustrated in Figure 19. To ease manufacturing
both features were integrated into the injection molded component.
In order to determine the required thickness of the steel plate FEM-simulations, in FEMAP, of
the plate were carried out. The plate was attached to the washer using the “closest links”
command, while the washer was simply fixed in space. The loads, 2.19 kN for each hole,
were applied to the top of the insides of the holes for the pin, see Appendix J. The required
plate thickness was estimated to 2 mm, when using a high strength steel such as SSAB’s
Docol 800. It was later realized that the project group lacked knowledge to use FEMAP
Figure 19. The circled areas represent the simplified and
integrated features for the assembly process to the vehicle.
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properly, thus the software was abandoned for Ansys, which was perceived as a more user
friendly software. Further simulations of the entire housing component, including the PUR
casing, the steel plate and the washer were carried out. Tetrahedron mesh was used for all
parts, the washer was constrained, as previously, in space and the metal plate was attached to
the washer using the “fixed” command. The loads were applied as in previous simulations, to
the top surfaces of the two holes at a magnitude of 2.19 kN per hole. These simulations
highlighted that the steel area above the hole were the critical area, as the high stresses
obtained at the bottom of the plate were discarded as singularities due to the constraints used,
Figure 20. The conclusions drawn were that when using a steel such as Docol 800 the plate
would not be an issue for the tensions tests, in fact a lesser steel grade might be used for mass-
production, however this needs to be verified through further simulations and physical testing.
7.1.1.3 Tongue
The material of the tongue was also replaced by an unfilled PUR material, thus it had to be
reinforced as well. The intention all along was to use X-TECH™ for this. The X-TECH™
reinforcement was to wrap around the pin at both ends and follow through the tongue as
described in Figure 21. In order to manufacture the X-TECH™ reinforcement a custom tool
was designed as well, Figure 22, this tool was to be 3D-printed as part of the prototype
production. Two versions of the tool were designed in order to produce two different sizes of
reinforcements, one circular cross section with Ø 3.5 mm, as this was the estimated required
thickness which was concluded through FEM-analysis, Appendix J. For the simulations the
ends of the pin were fixed in space while the X-TECH™ reinforcement was attached to both
the pin and the PUR body of the tongue using the “bonded” connection. The PUR body was
attached to the pin using “bonded” connections as well. The loads were applied as two
vectors. The vectors were of 3.097 kN respectively and resulted in a force of 4.38 kN, applied
as shown in Figure 21.
Figure 20. Illustrates the stresses in the plate and housing. As the housing is not of interest it is hidden in this picture, in
order to show the steel plate.
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As the results were hard to interpret due to the complexity of simulating anisotropic materials,
as well as the limited knowledge of FEM-software within the group Swerea Sicomp were
contacted in order to run the simulations and either verify or discard the previous results, as
they have prior experience of simulating X-TECH™. The simulations took into account the
anisotropicity of the X-TECH™ reinforcement as well as using refined material properties.
The results indicated that Ø 3.5 mm reinforcement would be at its very limit during the
tension tests, see Appendix K. Thus the reinforcement with an oval cross section of 3.5 x 5.0
mm was used for the prototypes, increasing the cross section area by approximately 50 %. In
order to house the reinforcement the thickness of the tongue had to be increased in some
areas, see Figure 23, as the X-TECH™ reinforcement requires at least 1 mm of plastic
material surrounding it.
Figure 21. To the left: Illustration of the tools used for producing the X-TECH™ reinforcement.
To the right: Enhanced view of the cavity which guides the pultruded X-TECH™ reinforcement.
Figure 22. To the left: An illustration of how the X-TECH™ reinforcement is integrated in to the
tongue. To the right: Illustration of the worst case loading scenario with a simplified model.
38. 32 | P a g e
This was a critical operation as space was limited because of the DIN 75410-2 standard
stating that a circular area of Ø20 mm was required in order to sell the product on the German
market, without offering any customized load loops. Regarding the friction elements, small
plastic components of which one was located at each end of the hole for the pin, these were
according to InXide possible to remove and instead integrated the function into the injection
molded PUR which would be used. Much effort was put in to re-creating the well-designed
surfaces of the current design, however since the group received a surface model as input for
CAD modeling this was a complicated task. Mainly due to the fact that the surface model
could only be used as a reference, the new model had to be created from scratch. In addition
to this inside of the top part of the hole in the tongue had to be slightly more rounded, in order
to fit the X-TECH™ reinforcement. The B-surface (backside of the tongue) was also changed,
the appearance and coherence to the current design, of this surface was not as important as the
A-surface (front side of tongue) since it would be hidden most of the time.
7.1.2 Interface design
The group feared that fitting the components together might be tricky as the tolerances were
quite tight and the friction when interacting with the load retention eye may be hard to mimic.
However, to the group’s surprise the interface design phase was a straightforward process due
to the surface model which was used as a reference. Even if mimicking the surfaces was hard
work deciding the boundaries of each component was easy. Since all dimensions of the three
components were based on this model they fit together in the same manner. The issues which
arose concerned leaving enough room for the washer and nut underneath the tongue as the B-
surface had been modified quite a lot. The solution was however as simple as removing
enough mass to enable the fit.
Figure 23. The circles illustrate the areas which had to be
thickened in order to fit the X-TECH™ reinforcement. The
tongue has been made transparent as to demonstrate how
the X-TECH™ reinforcement is fitted.
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7.1.3 System-level testing & Verification
The system level testing & verification phase consisted of four different types of verifications.
The tension testing of prototypes according to ISO 27955 and DIN 75410-2 standards, cost
estimations of manufacturing cost, FMEA-analysis and LCA-analysis.
7.1.3.1 Manufacturing of prototypes
The manufacturing process of the prototypes was in many aspects similar to how the process
would be built up for an actual product. The main difference was the use of silicon molds, as
this is a cost efficient way of producing prototypes, compared to injection molding tools.
The outsourced plate was manufactured by drilling holes into which the pin is fitted, the
plates were then cut into shape using a laser cutter. They were thereafter bent into their final
shape. The metal plates were then inserted in the silicon molding tools. Thus the steel plate
was molded to the housing, the final component was painted with a black coating, matching
the interior of the XC90. The pins were cut from a raw length rod to appropriate lengths and
the X-TECH™ reinforcement was laid out through pultrusion. For the production of the
tongue the reinforcement was fitted in the mold prior to molding. The cured tongue, housing
the reinforcement, was polished and a layer of paint was applied prior to chroming, in order to
make the chrome stick. When all three components were finished they were assembled, the
housing and the tongue were aligned and the pin inserted in order to connect the two, the
finished prototypes can be seen in Figure 24. The weighing of the finished prototypes
revealed a 57 % weight reduction, as the prototypes weighed 132 grams.
Figure 24. The photo shows one of the physical prototypes. In the background a
unit of the current LRE is visible. Photo taken by Jenny Netzler, Chalmers
University of Technology.
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7.1.3.2 Tension Testing
Ten prototypes were produced for testing, in order to confirm the results from the FEM
analysis. Out of these five were tested during the project. The other five were not finished in
time. These remaining five prototypes were handed over to InXide for future tests. The
tension testing took place at Volvo Car Corporation, the prototypes were mounted in the test
rig, as illustrated in Figure 25.
The two first prototypes were tested until breakage, in order to establish the breaking limit of
the load retention eye. Contrary to the expectations of the group the X-TECH™ reinforced
tongue broke first, however this was due to the brittle PUR used in the prototypes. The brittle
PUR broke first, leaving the X-TECH™ reinforcement without surrounding material. The
load was therefore not distributed along the reinforcement, leading to brakeage shortly after
the PUR. The reason for using this brittle material was a mixture of curing time and pressure
limits of the molds. The silicon tools cannot handle the pressures required to use a more
ductile PUR. The high pressures are required in order to fill the mold before the material starts
curing. The brittle PUR has a lower viscosity and thus fills the mold without the high
pressure. The conclusion was drawn that the brittle PUR did not distribute the load over the
fibers as intended, which resulted in a point load, leading to failure in that area. For the first
test breakage of the PUR occurred at 5.2 kN and at 4.1 kN for the X-TECH™ reinforcement.
The PUR of the second prototype broke at 4.5 kN and the X-TECH™ at 4.2 kN. These two
first runs indicated that the prototype was at its limits, as stated earlier this was due to the
brittle PUR. The three following test were carried out in accordance with ISO 27955 standard,
section 5.4 and DIN 75410-2 standard, section 5.4.3.
For the first and second of the three tests the prototype was initially loaded with a force of 1.5
kN for three minutes, in order to pass this test no separations were allowed and a maximum
residual deformation of 5 mm was allowed. The prototypes fulfilled these requirements, after
three minutes had passed the load was increased to 3.0 kN for another 3 minutes. In order to
pass this test no separations were allowed. The prototypes withstood this increased load as
well. When both tests had been successfully completed the load was increased until breakage
occurred.
For the third and final test the force was increased to 4.38 kN and applied for 30 seconds. The
prototype withstood the load for a few seconds before the plastic gave way. As the X-
TECH™ reinforcement was still in one piece the force was increased until breakage, which
without matrix material occurred at 4.63 kN. As noted earlier in this chapter, section 7.1.3 the
failure of the PUR matrix was likely due to the brittleness of the prototype material. The
physical tests show that, with the brittle PUR, the design is on the verge of complying with
both standards. With a more ductile PUR the force would be distributed more evenly over the
fibers, resulting in greater utilization of the entire fiber length. This ability to distribute the
load across large sections of the fibers is the main benefit of using a continuous fiber
reinforcement. The full test data is illustrated in Appendix K.
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7.1.3.3 Cost Estimations
The cost estimations were divided into three parts; internally manufactured components,
outsourced components and assembly of product. The parts classified as internally
manufactured included; the X-TECH™ reinforcement, the plastic housing and the plastic
tongue. These parts would be manufactured at KB Components site in Örkelljunga, Sweden,
since this is where InXide have their production cell. The X-TECH™ reinforcement would be
pultruded in this production cell while the housing and the tongue would be injection molded
in KB’s machine park. The outsourced parts consisted of the steel pin and the steel plate.
These parts would be transported to KB’s plant for assembly. For estimating the price of the
outsourced components the prices per kilo were identified for each component and the weight
of each component was estimated. The steel plate would, for mass production, be made of
SSAB’s Docol 800 DP steel, which is a formable high strength steel, common in automotive
safety details. The material price was based on Volvo Car Corporation’s current deals with
SSAB and is therefore classified, as most information used in the cost estimations. The pin
was manufactured from a steel named 115CrV3 (in the industry referred to as “silver steel”),
the material price was taken as a mean value from the CES EduPack materials database
(Granta-Design, 2014). The weight of these two components were estimated through
assigning material properties to the CAD model, the material data was taken from CES
EduPack as well. The total weight of the steel plate and pin was 67 grams and 6 grams
respectively. As no specific company had been identified the material cost was multiplied
with a factor of three for the steel plate and two for the pin. As there are internal numbers
involved the price per unit is classified.
Regarding the internally manufactured components; the X-TECH™ reinforcement, the plastic
housing and the plastic tongue the numbers are also internal and therefore classified. However
the procedure followed for these estimations are a lot more thorough and include; material
Figure 25. One of the prototypes prior to testing.
