Micro-finite element damage modeling in steel plate shear walls

Abstract

Collapse assessment of Steel Plate Shear Walls (SPSWs) requires thorough simulation of damage-induced softening by using deteriorating behavioral models. However, developing predictive equations that allow degradation modeling requires either costly experiments or detailed experimentally-verified micro finite element (FE) studies. The latter method is utilized in this study to simulate damage of infill plates using ductile damage theory. This starts by collecting all experimental results appropriate to the purpose. Next, an FE model is established and verified by comparing the model results against those of the experiments. The verification specifically concentrates on the damage model parameters whose dependency to specimens geometry is evaluated at the next stage. To this end, a Bayesian regression analysis is performed and a predictive equation is developed for future studies on modeling degradation of SPSW systems. An evaluation of the regression results is also used for obtaining an insight into the effect of SPSW geometry on damage initiation strain. This evaluation indicates that tensile damage starts at an equivalent plastic strain (EPS) of about 0.4 irrespective of SPSW properties. In compressive loading, however, the EPS at which damage starts ranges from 1000 to 4000. According to regression results, this strain reduces by increasing plate's aspect ratio while it increases by elevating plate's thickness or slenderness.