Repeated impact performance of stainless steel-lightweight high ductility cement composite beams

Abstract

Engineering structures serving in the marine environment may be subjected to multiple impact loading effects such as repeated impacts from floating ice, ship and dropped objects. Compared with reinforced concrete structures, steel–concrete–steel composite structures can maintain better integrity under continuous impacts due to the restraining effect of the external steel plates on the internal concrete. In this study, repeated impact tests are conducted to investigate the effect of different parameters on the multiple impact response of the stainless steel-lightweight high ductility cement composite (LHDCC) beam, which were previously designed by the authors. The failure modes, impact force history, displacement history, velocity history, strain history and reaction force–displacement curve of the composite beam under multiple impacts are analyzed in detail. Finite element simulation using LS-DYNA is carried out to investigate the impact and energy dissipation of the composite beams, in which the multi-drop hammer modeling method is proposed to simulate the multiple impact scenarios. To improve the simulation accuracy, uniaxial and triaxial tests on LHDCC materials are conducted to calibrate the parameters of the Continuous Surface Cap Model (CSCM) constitutive model. The numerical results are in good agreement with the experimental results.