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How to cope with a singularity in a report

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321GO

Automotive
Joined
Jan 24, 2010
Messages
345
Location
NL
Hi Guys,

In my assembly i have a stress singularity in the vicinity of the contact with another part of the assembly.

This location is of interest however, there is a decent amount of stress at this particular location, that i'm sure of. The FEA results though are a direct result of mesh size, stresses go to unreal value's.

Now the question:
What is the best approach fot such a situation in a final stress report:

a) mark the location as undefined? (this seems unacceptable to me though)

b) alter the geometry of the mate / parts, so that the boundry is less stiff? (this also seems unacceptable to me, since it would be a deliberate deviation from the actual assembly)

c) somehow do a handcalc to get some ball park value?


Would like to hear how you guys deal with such situations.


Thank you all in advance!




 
Although the stress at that location is unrealistic, the question should be as to how you classify the stresses at that location. As it's equivalent to say a point load, or a zero radius fillet say, then you'd classify the stresses as a peak stress component in addition to your primary and/or secondary stresses. The stress limit depends on the classification, ie. a primary membrane stress might be limited to 2/3 yield. prminary membrane plus bending to yield, and the primary plus peak stresses are limited to fatigue considerations, if they apply.

Hoping to say Tata
 
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