Limiting values for Von Mises

31mikey01

Hi there was wondering if anybody could help me.

1). How to find the limiting values of Von Mises stress induced in concentric reducers?
2). At what pressure concentric reducer will fail?
3). Calculation for thickness (minimum required for fittings) for ASME 1500 class rating.

Material properties:

WPHY65
Yeild = 450Mpa
Min. Tensile Strength = 535Mpa

Burst pressure value: 76.8Mpa

These questions have been forwarded to me after I had designed the reducer and created and FEA Results report. So asking for help with the above 3 questions.

Thanks

afreiden

Since you already have the FEA results, can't you just compare the von Mises stresses in the simulation to fy/sqrt(3)? Do you know where to look? Where do reducers usually fail when they fail? If it is a fracture problem, then you have to be careful in meshing your part, and you might want to consult a specialist in that sort of damage.

Vadar2012

I don't understand. Aren't these the questions you answer in your report. I do in mine. You have the material limits and the resultant stresses from the FEA. These are all you need really to answer those or are we missing something?

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afreiden	Since you already have the FEA results, can't you just compare the von Mises stresses in the simulation to fy/sqrt(3)? Do you know where to look? Where do reducers usually fail when they fail? If it is a fracture problem, then you have to be careful in meshing your part, and you might want to consult a specialist in that sort of damage.

Vadar2012	I don't understand. Aren't these the questions you answer in your report. I do in mine. You have the material limits and the resultant stresses from the FEA. These are all you need really to answer those or are we missing something?