It seems from your post that you are a student working on a project concerning distortion and residual stresses.
In general the residual stress reduces exponentially from the weld centre line in the transverse plane. However, the exact distribution of stress can be measured in a lab having facilities of 'hole drill type strain guage rossette' or x-ray diffraction stress analyser.
After welding a thick wide plate, a series strain guages need to be installed at different distances from the weld centre line. The values obtained could be plotted against distance.
This would give an idea of the residual stress distribution.
Hi
The simulation of welding via FEM is a rather complicated exercise because of the many variables, which constantly change as you weld. Usually people make so many assumptions when trying to do this, that they end up not really simulating the welding operation at all. At any rate, a lot of energy has gone into doing what you are trying. I have some references to papers that may be of help if you are interested. Why are you interested in this?
Regards
Niekie Jooste
Fabristruct Solutions
Simulating welding is a very difficult endeavor. First you have to have a moving heat source and to keep it simple, an autogenouse one. Ansys and Abacus are two programs that are often used for FEM on this subject. Prof. Tsai has published several papers on this subject at The Ohio State University, you should find him when you do a literature review. There has been a lot of research in Korea on this subject with applications for ship building.
Peter Kinney
I am very glad that so many friends answer my question .One friend said that I should do my literature review before my paper .Thank you for your suggestion ,but I am a student in asia .So I can't go to Ohio.Can you give me some electronic papers as my references?Thank you very much .I need your help .
Joanna which place do you stay in asia, possibly i could tell you where to go and whom to meet as I have travelled a lot in asia.
I am a chinese girl .Have you been in china?
ajoy
How about tell me how to get some information through internet.I want to know the general current in global . If some friends can give me some papers through e-mail ,thank you very much
Hope you got some information as referred by Andy.
Best wishes for your project.
Cheers.
Joanna -
Try typing "residual stress welding" into Google. Looks like there might be a few useful papers there. Here's a few links:
www.ias.ac.in/matersci/bmsapr2004/127.pdf
http://www.mt.mek.dtu.dk/reports/PHDthesis/abs/lfa.htm (This seems to be a Phd thesis so don't go copying this)
http://www.physiqueindustrie.com/residual_stress.htm
http://www.sercoassurance.com/featsite/case6/main.htm
Other useful sources of information might be the AWS welding handbook chapter 7, welding journals (welding in the world, quarterly journal of the japanese welding society)
Good luck in your search.
ajoy and andy
Thank you very much .I've try it .There are valuable papers.Thank you for your help .Now I have a had a general impression of the project .I think it is a good diretion . I find that different people do research from different angles .Can you tell me which is the most important factor in the analysis of residual stress in your opnion . As to me ,I want to find the effects of the weld shape .I think U or X shape will be better than V shape.So we can redue residual stress through choosing the better shape .Do you think it is a good idea ?
Nihou,
Probably you are talking about the groove design of the weld.
In general we have single bevel, double bevel, single vee, double vee, single J, double J, single U and double U designs.
The residual stress depends on the type of groove design and also on various welding parameters and base material characteristics. Example, no. of passes, tensile strength of the filler material, bead sequence, thickness of each pass etc.
Now, you can choose any one of the parameters to draw relations with residual stress. I can understand that groove design would be the most obvious choice for reserchers because of its simplicity, in my opinion you should take up a parameter which can be defined mathematically or can be expresses as a function of some other parameters. Thus, you will be able to come up with some equations.
Tell me if you need more guidance.
abhattacharyya@likpin.com
ajoy
nihao(hello)
You are very kind .
As you said my paper name should be "The Effects of groove design on Residual Stress"instead of "The Effects of Weld shape on Residual Stress" isn't it ?
My English is not very good especially when it comes to the specialized English .This time is the first time I talk with foreign friend except my foreign teachers.So I think it is a good chance to enhance my ability .
Yes I need your recommendation.
In detail I will simulate the procedure of welding through ANSYS.
Your suggestions are practial .I will take them into account .
Please give me more information .At the same time help me correct my English .Is This OK?
Nihao joanna,
yes, the title of your proposed paper should be ''Effects of groove design.....''
If you wish to present this paper in some international forum, your language should be presentable.
At the same time dont get bogged down with your english as it doesnt really matter if you are technically strong.
Years ago I took a course in physics. The teacher was a Korean man. I only wish his english had been half as good as yours (yours is fine).
Bill
billvanderhoof
My pleasure to hear your words .Your words encourage me to further my study .I will try my best to enhance my ability .However,I want to talk with you ,all of my friends on the bbs,fluently.I think the better my english is the more I can learn from you .
Can you tell me some electronic source to learn more words about welding ?I wish the words illustrate with some graphs.Of course I hope you may pay attention to my post and correct my mistakes .Thank you .
Do you have some suggestions about how to use FEM to analysis residual stress ?
Joanna -
I think what you are asking is very difficult to reply to for several reasons.
FEM is a complex subject and is you really need to speak to someone who has experience in FEM and particularly in modelling welding to analyse residual stresses.
FEM of welding is also very complex and a lot of large research organisations have done a lot of work on FEM of welds. Unfortunately, their work is usually funded by companies and the reports are confidential or at least restricted to thos companies who funded the work. Organisations that I can think of that fall into this category are:
The Welding Institute (TWI) www.twi.co.uk
Electricity and Power Research Institute (EPRI) www.epri.com
Edison Welding Institute (EWI) www.ewi.org
Battelle Memorial Institute Ohio. Pingsha Dong has published many papers on residual stresses in welds and if you can find his email, you could write to him to see if you could get some papers.
In addition a lot of universities around the work will also be involved in this type of work.
There seems to be a lot work that has been done in Asia, particualrly Korea and Japan in the shipbuilding industries.
I think that your best bet would be to visit the web pages and have a look at what information is freely available. TWI in particular have some very good free information on welding words, but be aware that American English and English English is not always the same.
Use the internet - it takes time to find useful information.
I found this this morning -
http://www3.sympatico.ca/peter_budgell/home.html
This looks like this could be very useful to you and it contains many links that are good. The author may be helpful to you in your work.
I hope this is useful.
Andy
andy
I have find some useful references floowing your first suggestion.
As you said you have do something about use FEM analyse residual stress ,what is the commercial software you have used?I will use ANSYS if I meet some problem in the process of simulation can you help me to solve some problem?
I have a very good friend who is an expert in FEM,he is in china, so I think I can do this research very good with all of the helps from allmy friends -you ajoy etc.Do you think so ?
At first I must do my literature review well.Later I will use ANSYS to do some works.
Good luck every day .
my email :joanajia@sohu.com
andy
I have found
The Welding Institute (TWI) www.twi.co.uk
Electricity and Power Research Institute (EPRI) www.epri.com
Edison Welding Institute (EWI) www.ewi.org
but it is very frustrated that I dont know how to regist.Firstly ,I searched the keywords"residual stress" .I found some results.Then I wanted to regist. But to my surprise the regist procedure is strange to me .I don't know how to regist .
Unfortunately, EPRI, TWI and EWI restrict the papers that they offer to the public as they are funded by member companies or individuals who pay a fee or are mebers of the organisation.
EWI do have some papers that are downloadable on residual stress. Type residual stress in the search box and open the papers from the list.
Andy
Thank you very much Andy ,I'd like to tell you that I have some progress
in my research .But I only do some somple examples . Now I want to further my study I would like to share my pleasure with you .If I gain any progress I will e-mail to you or post on here .
I waNT TO REFER TO
RESIDUAL STRESSES IN THICK WELDED PLATES.
The article can be found in
Welding Journal August 1972
welding research supplement p. 392-s - 405s ( 14 pages )
Material used : ASTM A 36
thickness : 1.5 to 6 in. ( 38mm to 152 mm)
process : stick welding ( manual electrode welding )
with kind regards
herbert
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