Weld stress analysis using axisymmetric model
Weld stress analysis using axisymmetric model
(OP)
I'm after some guidance on how to analyse welds based on stresses derived from an axisymmetric model. Basically the shape I am modelling is a can under internal pressrue with top and bottom covers fixed by single sided fillet welds. The designers have asked for confirmation that the weld throat size they have specifed is sufficient. To cut a long story short the bottom cover is fairly complex geometry and so although they have done some traditional hand calcs they want this backing up with FEA. Up to now I have only done fatigue assesments of welds, not actual design analysis and I am unsure how to approach this from FE when comparing the stresses to the allowable shear stress of the weld material. Would this be a use for the stress linerisation functions in Abaqus or similar? I am hoping using an axisymmetric model will make extracting the relevant stresses easier. Any advice would be of help. Thanks.





RE: Weld stress analysis using axisymmetric model
RE: Weld stress analysis using axisymmetric model
Weld sizing isn't an FEA task - you should be able to calculate it using hand calculations.
RE: Weld stress analysis using axisymmetric model
RE: Weld stress analysis using axisymmetric model
Just curious....if the model (and part) are axisymmetric why would you model it as a 3-D part????
Ed.R.
RE: Weld stress analysis using axisymmetric model
PS You don't need a 3D model and Von Mises stress isn't used for fatigue but assessment against yield.
corus
RE: Weld stress analysis using axisymmetric model
RE: Weld stress analysis using axisymmetric model
Respect fatigue, well, yes ... current practice goes along the line of identifying the detail as pertaining to a class, then the intricacies of the check are selfcontained and black-boxed to whatever stated about in the classification process. You are right, in another words.
However essentially what it is being done is a reduction on some limit stress or range of, and there may be cases where the details may not be directly amenable to one classed detail. So for critical applications you would modify the detail to one in the books, for other test and would ask for a class, and for others of lesser concern it might be agreed that a reduction of stresses limiting the overall behaviour might be useful.
RE: Weld stress analysis using axisymmetric model
Looking at the stress in the throat of the weld in a full 2D model may be confusing, as I think you'll still have some kind of stress distribution going on. Personally I'd run a simple axisymmetric model that you can definitely check by hand, and compare methods of evaluating the stress in the weld throat by FE just to be sure.
corus