DYNAMIC RESPONSE OF PLATES TO MOVING LOADS: STRUCTURAL IMPEDANCE AND FINITE ELEMENT METHODS

To study the transient response of plates with arbitrary boundary conditions to moving loads, two algorithms have been developed. The first algorithm is based on a structural impedance approach and the second adopts a finite element approach. A thin plate theory is assumed for the plate model. General viscoelastic foundation support can be introduced as a series of springs and dashpots lumped at the nodes. The algorithms place no restrictions on the loading conditions. For illustrations, the study considers two parallel moving loads with suspension systems. Two general purpose computer codes PLATEIMP and PLATEFEM were developed. These two codes are used to study the dynamic response of plates as they interact with the moving loads. Although the PLATEFEM program is more versatile than the PLATEIMP program in application, both programs account for the complete dynamic interactions between the moving loads and the plate structure. Thus the computer codes can be applied to the general moving mass problems and simplified moving force and static problems. The accuracy of the algorithms and the corresponding codes are verified by comparing the numerical results, in the case of moving force solutions, with the exact solutions and with other numerical results. A parametric study concerning the effects of speed, acceleration, damping and the suspension system is also presented.