Biaxial Yielding Failure Criteria
Biaxial Yielding Failure Criteria
(OP)
Hi,
I have a problem in which I have a metallic liner (AL6061-T4) in a pressure vessel which is designed to yield biaxially during pressurization. My question is, what would be the ultimate failure criteria for this condition? That is, what combined stress state would be the most appropriate to predict exceeding ultimate allowables?
I know that the von mises yield criterion is used to predict onset of yielding, however it loses meaning to use this criteria beyond the point of yielding from my understanding.
Would maximum principal stress/strain be appropriate to predict failure in a situation like this?
Thanks for your input...
I have a problem in which I have a metallic liner (AL6061-T4) in a pressure vessel which is designed to yield biaxially during pressurization. My question is, what would be the ultimate failure criteria for this condition? That is, what combined stress state would be the most appropriate to predict exceeding ultimate allowables?
I know that the von mises yield criterion is used to predict onset of yielding, however it loses meaning to use this criteria beyond the point of yielding from my understanding.
Would maximum principal stress/strain be appropriate to predict failure in a situation like this?
Thanks for your input...





RE: Biaxial Yielding Failure Criteria
RE: Biaxial Yielding Failure Criteria
RE: Biaxial Yielding Failure Criteria
I was reading your post and am a little confused as to what your intentions are with respect to the vessel and liner. The pressure vessel would not be designed to yield if you are using any of the accepted pressure vessel construction codes. Most international codes that use design-by-rule do not allow for primary membrane stress to exceed yield in service based on use of allowable stress values.
If your discussion pertains to the liner itself, the criterion for failure will be allowing for some acceptable level of permanent distortion if you are assuming that the liner will be subjected to service stresses that exceed current code allowable stresses. You will also need to evaluate what damage mechanism prevails in service. If this pressure vessel is cycled or you have thermal cycling, low cycle fatigue will be the controlling variable for this liner.
RE: Biaxial Yielding Failure Criteria