Strain Rate Effect on the Progressive Collapse Analysis of RC Frame Structure under Earthquake

Abstract

The strain rate effect can influence the seismic responses of reinforced concrete (RC) structures because the constitutive relationship of concrete and rebar is rate-dependent. This paper carries out progressive collapse analysis to research the influence of strain rate effects on collapse-resistant capacity, collapse mode, and collapse path of the RC frame structure. A progressive collapse simulation program for the reinforced concrete (RC) structure with a static and dynamic constitutive relationship is coded individually using the user subroutine VUMAT and then implemented in the advanced finite element program ABAQUS. The good agreement between experimental and simulation results proves that the coded subroutine is reliable. With the coded subroutine, by conducting progressive collapse analyses of a four-story RC frame structure under earthquake, the effect of strain rate on the response is investigated. The numerical results demonstrate that the collapse-resistant capacity of the structure is underestimated when the strain rate effect is neglected. It is shown that strain rate effects influence the collapse mode and collapse path of the structure. Therefore, strain rate effects should be considered in the progressive collapse analysis of the RC frame structure.