Stochastic Load Exceedances with General Material Nonlinearity

Abstract

Reliability of a structural member with nonlinear material property subjected to floor live‐load processes is investigated. Earlier studies have assumed a bilinear load‐deformation relationship. However, the actual force‐deformation relationship exhibits a nonlinear curve, even for a very simple system. In this study, a multilinear load‐deformation model that can better approximate the actual material behavior is utilized. The first‐moment statistics are derived for the number of load exceedances and damage duration for a structural member due to sustained and combined load processes. It is found that the derived results using a trilinear material model agree very well with the results obtained from simulated data. The differences are usually within 3% for sustained load processes and somewhat higher, about 10%, for combined processes.