Energy Dissipation of Ordinary Concrete under Discontinuous Cyclic Compression Loading and Numerical Simulation of the Residual Stress

Abstract

This study experimentally investigates ordinary concrete under discontinuous cyclic compression loading and performs numerical simulation of the residual stress. The stress cycles in discontinuous cyclic compression tests are interrupted by zero or very low loading intervals (ZLIs). The fatigue tests revealed that the dissipated energy and unloading deformation modulus of a cycle after the ZLI (A cycle) are significantly higher than those of the cycle before the ZLI (B cycle). The dissipated energy and unloading deformation modulus increase with an increase in the stress level. The cumulative rate of fatigue damage in the A cycles is noticeably higher than that in B cycles. The mechanism of discontinuous fatigue is influenced by the residual stress caused by an uncoordinated mechanical response. Moreover, the simulation results indicated that stress concentration occurs in the interfacial transition zone between the aggregate and the cement paste matrix, and the residual stress and plastic deformation increase as the difference between the elasticity modulus of the aggregate and the matrix increases.