Pattern allowances are extra material added to patterns to account for shrinkage and other factors during the casting process. Patterns are larger than the final casting size. Allowances include shrinkage allowance for metal contraction, machining allowance for finishing, and draft allowance so patterns can be easily removed from molds. Proper allowances and pattern design can reduce defects and costs in metal casting.
Buckling Analysis of Cold Formed Steel Compression Members at Elevated Temper...IJMER
Abstract: Cold-formed steel members have been widely used in residential, industrial and commercial
buildings as primary load bearing structural elements due to their advantages such as higher strength to
weight ratio over the other structural materials such as hot-rolled steel, timber and concrete. However,
they are susceptible to various buckling modes including local and distortional buckling. Fire safety
design of building structures has received greater attention in recent times as fire events can cause loss
of property and lives. Therefore it is essential to understand the fire performance of light gauge coldformed
steel structures under fire conditions. The buckling behavior of cold-formed steel compression
members under fire conditions is not well investigated yet and hence there is a lack of knowledge on the
fire performance of cold-formed steel compression members. Therefore, this paper deals with behavior
of cold formed steel compression member under fire and to analyze the effect of fire on critical buckling
load of compression member. Eigen value analysis for Lipped channel sections made of various
thicknesses and both low and high strength steels was carried out through finite element method. The
ultimate load carrying capacity results from experimental investigation and finite element analyses were
then compared
its sheet metal working for non ferrous metal and alloy. its show all process like punching, deep drawing, etc which can employ in sheet metal working.its show how process done in short details.
Introduction to Manufacturing Processes and their Applications (Casting, Forging, Sheet metal working and Metal joining processes), Description of Casting process: Sand casting(Cope&Drag). Sheet metal Forming,(shearing, bending, drawing), Forging (Hot working and cold working comparison) ,Electric Arc welding, Comparison of Welding, Soldering, Brazing
Finite Element Analysis of Cold-formed Steel ConnectionsCSCJournals
This paper presents a thorough investigation into the structural performance of cold-formed steel column base and beam column connections using single lipped C sections with bolted moment connections. Two specimens consisting of a column base and a beam column connection were carried out, and it was found that section failure under flexural buckling was always critical. Moreover, the proposed connections were demonstrated to be structurally efficient attaining moment resistances close to those of the connected sections. In order to examine the structural behavior of the column base and beam column connections, finite element models were established using shell and bar elements to model the sections and the bolted fastenings respectively. Material non-linearity was incorporated, and comparison between the test and the numerical results was presented in details. It was shown that the proposed analysis method was structurally adequate to predict the structural behavior for column base and beam column with similar connection configurations.
Welding Defects
Eurotech Now inteducing Welding Defects. Welding Defect is any type of flaw in the object which requires welding. Seven type of Welding Defect
Seven type of Common weld defects include:
1. Lack of fusion
2. Lack of penetration or excess penetration
3. Porosity
4. Inclusions
5. Cracking
6. Undercut
7. Lamellar tearing
Any of these defects are potentially disastrous as they can all give rise to high stress intensities which may result in sudden unexpected failure below the design load or in the case of cyclic loading, failure after fewer load cycles than predicted.
Buckling Analysis of Cold Formed Steel Compression Members at Elevated Temper...IJMER
Abstract: Cold-formed steel members have been widely used in residential, industrial and commercial
buildings as primary load bearing structural elements due to their advantages such as higher strength to
weight ratio over the other structural materials such as hot-rolled steel, timber and concrete. However,
they are susceptible to various buckling modes including local and distortional buckling. Fire safety
design of building structures has received greater attention in recent times as fire events can cause loss
of property and lives. Therefore it is essential to understand the fire performance of light gauge coldformed
steel structures under fire conditions. The buckling behavior of cold-formed steel compression
members under fire conditions is not well investigated yet and hence there is a lack of knowledge on the
fire performance of cold-formed steel compression members. Therefore, this paper deals with behavior
of cold formed steel compression member under fire and to analyze the effect of fire on critical buckling
load of compression member. Eigen value analysis for Lipped channel sections made of various
thicknesses and both low and high strength steels was carried out through finite element method. The
ultimate load carrying capacity results from experimental investigation and finite element analyses were
then compared
its sheet metal working for non ferrous metal and alloy. its show all process like punching, deep drawing, etc which can employ in sheet metal working.its show how process done in short details.
Introduction to Manufacturing Processes and their Applications (Casting, Forging, Sheet metal working and Metal joining processes), Description of Casting process: Sand casting(Cope&Drag). Sheet metal Forming,(shearing, bending, drawing), Forging (Hot working and cold working comparison) ,Electric Arc welding, Comparison of Welding, Soldering, Brazing
Finite Element Analysis of Cold-formed Steel ConnectionsCSCJournals
This paper presents a thorough investigation into the structural performance of cold-formed steel column base and beam column connections using single lipped C sections with bolted moment connections. Two specimens consisting of a column base and a beam column connection were carried out, and it was found that section failure under flexural buckling was always critical. Moreover, the proposed connections were demonstrated to be structurally efficient attaining moment resistances close to those of the connected sections. In order to examine the structural behavior of the column base and beam column connections, finite element models were established using shell and bar elements to model the sections and the bolted fastenings respectively. Material non-linearity was incorporated, and comparison between the test and the numerical results was presented in details. It was shown that the proposed analysis method was structurally adequate to predict the structural behavior for column base and beam column with similar connection configurations.
Welding Defects
Eurotech Now inteducing Welding Defects. Welding Defect is any type of flaw in the object which requires welding. Seven type of Welding Defect
Seven type of Common weld defects include:
1. Lack of fusion
2. Lack of penetration or excess penetration
3. Porosity
4. Inclusions
5. Cracking
6. Undercut
7. Lamellar tearing
Any of these defects are potentially disastrous as they can all give rise to high stress intensities which may result in sudden unexpected failure below the design load or in the case of cyclic loading, failure after fewer load cycles than predicted.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
TECHNICAL TRAINING MANUAL GENERAL FAMILIARIZATION COURSEDuvanRamosGarzon1
AIRCRAFT GENERAL
The Single Aisle is the most advanced family aircraft in service today, with fly-by-wire flight controls.
The A318, A319, A320 and A321 are twin-engine subsonic medium range aircraft.
The family offers a choice of engines
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Courier management system project report.pdfKamal Acharya
It is now-a-days very important for the people to send or receive articles like imported furniture, electronic items, gifts, business goods and the like. People depend vastly on different transport systems which mostly use the manual way of receiving and delivering the articles. There is no way to track the articles till they are received and there is no way to let the customer know what happened in transit, once he booked some articles. In such a situation, we need a system which completely computerizes the cargo activities including time to time tracking of the articles sent. This need is fulfilled by Courier Management System software which is online software for the cargo management people that enables them to receive the goods from a source and send them to a required destination and track their status from time to time.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
COLLEGE BUS MANAGEMENT SYSTEM PROJECT REPORT.pdfKamal Acharya
The College Bus Management system is completely developed by Visual Basic .NET Version. The application is connect with most secured database language MS SQL Server. The application is develop by using best combination of front-end and back-end languages. The application is totally design like flat user interface. This flat user interface is more attractive user interface in 2017. The application is gives more important to the system functionality. The application is to manage the student’s details, driver’s details, bus details, bus route details, bus fees details and more. The application has only one unit for admin. The admin can manage the entire application. The admin can login into the application by using username and password of the admin. The application is develop for big and small colleges. It is more user friendly for non-computer person. Even they can easily learn how to manage the application within hours. The application is more secure by the admin. The system will give an effective output for the VB.Net and SQL Server given as input to the system. The compiled java program given as input to the system, after scanning the program will generate different reports. The application generates the report for users. The admin can view and download the report of the data. The application deliver the excel format reports. Because, excel formatted reports is very easy to understand the income and expense of the college bus. This application is mainly develop for windows operating system users. In 2017, 73% of people enterprises are using windows operating system. So the application will easily install for all the windows operating system users. The application-developed size is very low. The application consumes very low space in disk. Therefore, the user can allocate very minimum local disk space for this application.
NO1 Uk best vashikaran specialist in delhi vashikaran baba near me online vas...Amil Baba Dawood bangali
Contact with Dawood Bhai Just call on +92322-6382012 and we'll help you. We'll solve all your problems within 12 to 24 hours and with 101% guarantee and with astrology systematic. If you want to take any personal or professional advice then also you can call us on +92322-6382012 , ONLINE LOVE PROBLEM & Other all types of Daily Life Problem's.Then CALL or WHATSAPP us on +92322-6382012 and Get all these problems solutions here by Amil Baba DAWOOD BANGALI
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CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Quality defects in TMT Bars, Possible causes and Potential Solutions.PrashantGoswami42
Maintaining high-quality standards in the production of TMT bars is crucial for ensuring structural integrity in construction. Addressing common defects through careful monitoring, standardized processes, and advanced technology can significantly improve the quality of TMT bars. Continuous training and adherence to quality control measures will also play a pivotal role in minimizing these defects.
2. Pattern is a model or the replica of the object to be cast. It is a larger
in size as compared to the final casting, because it carries certain
allowances due to metallurgical and mechanical reasons for example,
shrinkage allowance is the result of metallurgical phenomenon where
as machining, draft, distortion, shale, and other allowances are
provided on the patterns because of mechanical reasons.
Top center is the clay original, then the two
part plaster mold used for casting the lead at
above, and wax cast from mold, sprued for
better brass casting, not yet cast. 2008-01-12.
homepages.waymark.net/mikefirth/tapper688
1b.jpg
3. Functions of Patterns:
• A Pattern prepares a mould cavity for the
purpose of making a casting.
• A Pattern may contain projections known as
core prints (corazón) if the casting requires a
core and need to be made hollow.
• Patterns properly made and having finished
and smooth surfaces reduce casting defects.
• Properly constructed patterns minimize
overall cost of the casting.
4. The pattern material should be:
1.
2.
3.
4.
5.
6.
7.
Easily worked,shaped and joined.
Light in weight.
Strong,hard and durable.
Resistant to wear and abrasion .
Resistant to corrosion,and to chemical
reactions.
Dimensionally stable and unaffected by
variations in temperature and humidity.
Available at low cost.
11. Reason for allowances:
Solidification Shrinkage
Most metals undergo
noticeable volumetric
contraction when cooled
Three principle stages of
shrinkage:
Shrinkage of liquid as it
cools from the solidification
temperature
Solidification shrinkage as
the liquid turns into solid
Solid metal contraction as
the solidified metal cools to
room temperature
Figure Dimensional changes experienced by a
metal column as the material cools from a
superheated liquid to a room-temperature solid.
Note the significant shrinkage that occurs upon
solidification.
12. Prediction of porosity after casting
Minuto 1:12. Se observa la contracción del metal, no hay tolerancia para
compensarla, genera porosidad residual.
14. Dimensional Allowances
Typical allowances
Cast iron 0.8-1.0%
Steel 1.5-2.0%
Aluminum 1.0-1.3%
Magnesium 1.0-1.3%
Brass 1.5%
Shrinkage allowances are incorporated into the
pattern using shrink rules
Thermal contraction might not be the only factor for
determining pattern size
Surface finishing operations (machining, etc.)
should be taken into consideration
15. Solidification Shrinkage
Amount of liquid metal contraction depends on the
coefficient of thermal contraction and the amount of
superheat
As the liquid metal solidifies, the atomic structure
normally becomes more efficient and significant
amounts of shrinkage can occur
Cavities and voids can be prevented by designing the
casting to have directional solidification
Hot tears can occur when there is significant tensile
stress on the surface of the casting material
16. Types of Pattern Allowances:
THE VARIOUS PATTERN
ALLOWANCES ARE:
1.
2.
3.
4.
Shrinkage or contraction allowance.
Machining or finish allowance.
Draft of tapper allowances.
Distortion or chamber allowance.
5. Shake or rapping allowance.
17. 1.ShrinkageAllowance:
All most all cast metals shrink or contract
volumetrically on cooling.
1.Liquid Shrinkage:
it refers to the reduction in volume when the metal
changes from liquid state to solid state at the solidus
temperature.To account for this shrinkage;riser,which
feed the liquid metal to the casting,are provided in the
mold.
2.Solid Shrinkage:
it refers to the reduction in volume caused when
metal loses temperature in solid state.To account for
this,shrinkage allowance is provided on the patterns.
18. Almost all cast metals shrink or contract
volumetrically after solidification and therefore the
pattern to obtain a particular sized casting is made
oversize by an amount equal to that of shrinkage
or contraction.
Different metals shrink at different rates because
shrinkage is the property of the cast metal/alloy.
The metal shrinkage depends upon:
1. The cast metal or alloy.
2. Solidification temp.of the metal/alloy.
3. Casted dimensions(size).
4. Casting design aspects.
5. Molding conditions(i.e.,mould materials
and molding methods employed)
19. Material Dimension Shrinkageallowance
(inch/ft)
Grey Cast Iron
Up to 2 feet
2 feet to 4feet
Over 4feet
0.125
0.105
0.083
CastSteel
Upto2feet
2feetto6feet
over6feet
0.251
0.191
0.155
Aluminum
Upto4feet
4feetto6feet
over6feet
0.155
0.143
0.125
Magnesium Upto4feet
Over4feet
0.173
0.155
RATE OF CONTRACTION OF VARIOUS METALS :
20. i.
ii.
iii.
iv.
i.
ii.
iii.
2.MachiningAllowance:
A CASTING IS GIVEN AN ALLOWANCE FOR MACHINING, BECAUSE:
Castings get oxidized in the mold and during heat
treatment;scales etc.,thus formed need to be removed.
It is the intended to remove surface roughness and other
imperfections from the castings.
It is required to achieve exact casting dimensions.
Surface finish is required on the casting.
HOW MUCH EXTRA METAL OR HOW MUCH
MACHINING ALLOWANCE SHOULD BE
PROVIDED, DEPENDS ON THE FACTORS LISTED BELOW:
Nature of metals.
Size and shape of casting.
The type of machining operations to be employed for
23. 3.Draft or TaperAllowance:
It is given to all surfaces perpendicular to parting
line.
Draft allowance is given so that the pattern can
be easily removed from the molding material
tightly packed around it with out damaging the
mould cavity.
The amount of taper depends upon:
i. Shape and size of pattern in the depth
direction in contact with the mould cavity.
ii. Moulding methods.
iii. Mould materials.
iv. Draft allowance is imparted on internal as well
as external surfaces;of course it is more on
internal surfaces.
30. 4. Distortion or cambered allowance:
A CASTING WILL DISTORT OR WRAP IF :
i. It is of irregular shape,
ii. All it parts do not shrink uniformly i.e.,some
parts shrinks while others are restricted from
during so,
iii. It is u or v-shape,
iv. The arms possess unequal thickness,
v. It has long,rangy arms as those of propeller strut
for the ship,
vi. It is a long flat casting,
vii. One portion of the casting cools at a faster rate
31.
32. 5.Shake allowance:
A patter is shaken or rapped by striking the same
with a wooden piece from side to side.This is
done so that the pattern a little is loosened in the
mold cavity and can be easily removed.
In turn,therefore,rapping enlarges the mould
cavity which results in a bigger sized casting.
Hence,a ²ve allowance is provided on the pattern
i.e.,the pattern dimensions are kept smaller in
order to compensate the enlargement of mould
cavity due to rapping.
The magnitude of shake allowance can be
reduced by increasing the tapper.
33. Pattern Layout:
Steps involved:
Get the working drawing of the part for
which the pattern is to be made.
Make two views of the part drawing on a
sheet,using a shrink rule. A shrink rule is
modified form of an ordinary scale which has
already taken care of shrinkage allowance for
a particular metal to be cast.
Add machining allowances as per the
requirements.
Depending upon the method of molding,
provide the draft allowance.
34. Pattern Construction:
Study the pattern layout carefully and establish,
a. Location of parting surface.
b. No.of parts in which the pattern will be made.
Using the various hand tools and pattern making
machines fabricate the different parts of the pattern.
Inspect the pattern as regards the alignment of
different portions of the pattern and its dimensional
accuracy.
Fill wax in all the fillets in order to remove sharp
corners.
Give a shellac coatings(3 coats) to pattern.
impart suitable colors to the pattern for
identification purposes and for other informations.
35. Design Considerations in Castings
Location and orientation of the parting line is important
to castings
Parting line can affect:
Number of cores
Method of supporting cores
Use of effective and economical gating
Weight of the final casting
Final dimensional accuracy
Ease of molding
36. Design Considerations
Various allowances incorporated into a
casting pattern.
Two-part mold showing the parting line and the
incorporation of a draft allowance on vertical
surfaces.
37. Design Considerations
Figure 11-16 (Left) Elimination of a core by
changing the location or orientation of the
parting plane.
Figure 11-17 (Right) Elimination of a dry-
sand core by a change in part design.
38. Design Considerations
It is often desirable to minimize the use of cores
Controlling the solidification process is important
to producing quality castings
Thicker or heavier sections will cool more slowly, so
chills should be used
If section thicknesses must change, gradual is better
If they are not gradual, stress concentration points can be
created
Fillets or radii can be used to minimize stress concentration
points
Risers can also be used
39. Parting Line and Drafts
Figure 11-18 (Top left) Design where the location of the parting plane is specified by the
draft. (Top right) Part with draft unspecified. (Bottom) Various options to produce the top-
right part, including a no-draft design.
40. Section Thicknesses
(Above) Typical guidelines for section change transitions in castings.
Figure a) The “hot spot” at section r2 is cause by intersecting sections. B) An interior fillet and exterior
radius lead to more uniform thickness and more uniform cooling.
41. Design Modifications
Hot spots are areas of the material that cool more
slowly than other locations
Function of part geometry
Localized shrinkage may occur
Hot spots often result from intersecting sections of various thickness.
42. Design Modifications
Parts that have ribs may experience cracking due to
contraction
Ribs may be staggered to prevent cracking
An excess of material may appear around the parting
line
The parting line may be moved to improve appearance
Thin-walled castings should be designed with extra
caution to prevent cracking