Numerical Simulation On The Elastic-plastic Wave Propagation In Framed Structures

The characteristic of near-field ground motion is difference from that of far-field ground motion so that the failure patterns of buildings impacted by the near-field strong earthquake motion and the far-field strong earthquake motion are different. Because some new faileure patterns couldn't be explained well by the traditional methods, the method of wave propagation is attempted to slove the problem.Firstly, the elastic wave propagation in framed structures by finite difference method is investigated. The consideration of longitudinal,torsional and flexural waves in rigid frames yields the finite difference equation for wave propagation in framed structures, The explame study shows that the finite difference method can simulate the elastic wave propagation in framed structures effectively.Secondly, a double-deck difference equation for the plastic wave propagating in framed structures is formulated by the combination of normal finite difference method in the spacial domain and Wilson-θmethod in the time domain. It is assumed that the constitutive relations of material are independent in three directions. Bilinear restoring force characteristics and Masing rule are also used in the research. The numerical examples study shows that the new finite difference method can simulate the plastic wave propagation in framed structures well.It is shown that the finite difference method could be further applied in the numerical simulation to the elastic-plastic wave propagation in hinged point structures or mixed point structures and to the investigation of the damage mechanism of structures impacted by the near-field strong earthquake motion.