Abstract
Combined normal stresses (σ1 and σ2) were applied to tubular specimens normal and parallel to the material axes. In all cases, acoustic emissions (AE) were measured in details for distinguishing damage accumulation. The S-S relationships in both directions were not strongly affected by a biaxial stress ratio, α(=σ1/σ2) in comparison with the S-S relationships under tension/shear biaxial loading since the load was primarily sustained by fibers under tension/tension biaxial loading in the material axes. The S-S curves in both direction are represented by two straight lines intersecting with each other at their knee points while the secondary knee does not appear as soon as the first knee has been observed except at α=1/1. Consequently, the initial yield stress condition is represented by two lines parallel to either σ1 or σ2 axes. They are drawn based on the knee stresses at α=1/0 and 0/1. The maximum stress theory fits the experimental failure envelope better than the Tsai-Wu failure criterion.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
