Testing and Numerical Analysis of Elastoplastic Steel Column Impacted by Rigid Body

摘要

The experimental and computational results of a steel column impacted by hammer are presented here. The focus of the experiments was the measurement of buckling location and stress wave propagation. There were ten test impacts with the same nominal impact conditions arrangements. Dropping hammer impact testing machine is used to carry on the axial impact experiment of pipe columns made of Q235 steel, the strain time history curve on symmetrical surface of round pipe specific section has been recorded with dynamic strain gauges and instruments, divergence time was gotten. Buckling moment and buckling location and buckling deformations are gotten from the analysis of experimental data. A series of numerical simulations are performed in order to understand the buckling mechanism by FEM method and they are compared with the experiment. The buckling procedure of column impacted by rigid body is simulated by introducing initial geometric imperfection with ABAQUS/Explicit analysis module. An energy criterion determining buckling is proposed here as the numerical buckling law. Based on the law, the influence factors of dynamic buckling are analyzed. The test and calculation results show that: When the mass ratio a in the impact system is constant, the shorter the column is, the earlier the buckling occurs, and the higher the critical buckling velocity. Critical buckling times decrease with the impact velocity and Ma. The critical buckling velocity decreases with Ma. Boundary support conditions of the impacted end have significant influences on the buckling moment. For the effect of materials on buckling moment, elastic column buckles first, the linear hardening elastoplastic column buckles the latest, and the rate-dependent elastoplastic column falls in between.