ISO 13628 Linearised Stress

[cjkelly83]

Looking for some advice on stress linearisation, specifically how to deal with shear dominated stress paths.


A consulting company has performed analysis on a threaded pipe connector subject to bending, tension and compression. They have calculated the capacity of the connector based on ISO 13628. The bending capacity is greatly limited by the threads on the tensile side of the connector. The company has linearised a path through the threads and set the limit based on Membrane + Bending along the path. Due to nature of the thread the stress is greatly dominated by shear, is it still correct to be checking the path for membrane + Bending or should it be a pure shear check?

Note the pipe is a structural component and is subject to tension/compression and bending only and not pressure (internal or external)

 

[CoryPad]

Is the thread internal or external?

 

[cjkelly83]

Hi Cory the thread is internal, i have attached a couple of images which show the paths checked and also VM stress plots from Ansys

 

[CoryPad]

Shear stress in the internal threaded region is high when there is an axial force (pretension, mass of piping, etc.) applied. For this application with an applied moment, the shear is not necessarily the dominant stress. The von Mises plots look accurate. I am not sure the paths have been selected correctly.