As far as I know, Non-Linear analysis is when Hooke's Law does not apply right? it's when a material is stressed beyond it's elastic limit. My question is, in STAAD Compresion/tension only members/support are considered non-linear, I'm wondering how is that related to Hooke's Law? or are there any other criteria for an analysis to be considered as non-linear? I'm sorry I'm bit noob in non-linear analysis.
Thank you in advance.