Protection Against Local Failure Examples 2

[Doodler3D]

Hi,

I was going through some of the concepts (hydrostatic stress state, triaxiality and material microstructure) that have led to the formulation of protection against local failure in the ASME Sec VIII Div. 2 code, but could not find examples of actual failure in technical publications. Has someone come across articles where equipment failure was driven specifically by local collapse? Or, is that not possible.

Thank you.

 

[TGS4]

Excellent question. We have had multiple discussions on this topic at the Code Committee level. Several failures have been shown and discussed, but I am unsure if any of them have been published into the literature.

If you contact me off-line, I will see what I can share with you. Unfortunately, I am unable to share what I have publicly.

 

[Doodler3D]

@TGS4 I was able to get 'Fracture And Fatigue Control in Structures' by S Rolfe and now things are a little clearer. One would see this failure at a section where the triaxial strain state is highly tensile and subsequently embrittled. If the section is large enough to not be 'local', it will lead to collapse. I could find an example from an offshore/subsea application "Local Failure Analysis of HPHT Subsea Tree Components due to Triaxial Stress" by K. Karpanan. I am assuming that the lack of information is due to the absence of quantifiable experimental data and the lack of incidences of this failure mode with terrestrial applications.