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Simulate Weldment analysis problem

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Simulate Weldment analysis problem

I am currently having a very diificult time producing a static analysis of a weldment assembly. I generate a working mesh, and when I run the analysis the solver throws back loads of errors reading " ??? ". I am relatively inexperienced in the simulation side with Creo, and I wondered if anyone can point me in the general direction as to the reason I am expericing these these errors. I have uploaded a screen shot showing the erro thrown back from the solver, the basic outcome is that the ignored links generate huge and inaccurate stress concentrations at the weld shell connection to the solid.

Any advice would be gratefully received.

Thanks

5 REPLIES 5

Re: Simulate Weldment analysis problem

Daniel,

There are a lot of contacts, some free connections, weld idealisations and red elements (insufficiently constrained?)

If you upload the ,rpt, .stt files (and model?) someone maybe able to assist further.

Regards

Re: Simulate Weldment analysis problem

Hi Charles,

Firstly and foremost I wish to thank you for posting on my query.

I am currently analysing/reviewing a full range of similar designs, and so I have attached the model file to get some helpful feedback. You can download the model at https://drive.google.com/a/ceaprojects.com/folderview?id=0B5oaO7Q5cLfXaDBMdkRfM3gzZVE&usp=sharing

I have set up weld and interface connections for the contact surfaces between individual components. Generating the mesh and checking the model is always passed, the problem that I am not understanding is to why the solver throws back the message "The angle between the normal to the shell and the normal to the solid face at a shell-solid link must be greater than 45 degrees. The link(s) will be ignored." This error only appears at the weld interfaces between the weld quilt idealisation and the solid which is on the curvature of the chs section.

If you have the time to review my mdel and have any experience in setting on the simulation so that these error do not occur I would be endebted to you.

Thank you

Yours Faithfully

Daniel

Re: Simulate Weldment analysis problem

Hi Daniel,

I am not sure whether anybody visiting the thread, could access the files.

At least I failed. Google asked me for a login I don't have.

If your file does not exceed 100 MB, you can upload it to this thread, when you switch from Simple Editor to Advanced Editor.

Gunter

Re: Simulate Weldment analysis problem

Dear all,

Thank you very much for your replies. I have attached the *.rar file with the files you can download to help review my query.

Thank you all, and I appreciate any advice you can give in setting up my analysis such that I don't have errors at the component interfaces, I will have to undertake severral similar analysis, so anything I learn through PTC community would be highly appreciated.

Yours Respectfully

Daniel

Re: Simulate Weldment analysis problem

... inaccurate stress concentrations at the weld shell connection to the solid.

This is because there are singular results at the connection between solid and shell elements. Multipoint constraint equations (or 'links' which show up as those pink lines) are required to connection solid to shell elements due to the nodal incompatibility that exists between the two; that is, solid elements have only three DOF (all translation) while shell elements have six DOF.

It's unrealistic to try and get accurate stress results in the area directly occupied by a weld. It's more realistic to look at the stress results in the material near the weld (but not within it) and/or look at the internal forces within the weld and compare them against analytical methods. Also keep in mind that, unless you have a full penetration weld, you need to consider fracture mechanics when trying to determine if a weld is good enough.