Consider The Poisson Effect Of Flexible Rod Collision Dynamic Substructure Method

In this dissertation a dynamic substructure method is applied to the research for the influence of poisson effect to impact problem of flexible body. The problem of a flexible bar struck longitudinally at its free end by a rigid body moving at a finite velocity was investigated by the fixed-interface mode synthesis substructure technique. The impact model is analyzed, and the dynamics model is dispersed with the substructure method. The dynamics equation expressed with modal coordinates, which has fewer degree of freedom, is derived from the lagrange's equation. The rule of substructure discretization of flexible bar is achieved. It is shown that when each substructure is divided into 3 elements, 50 substructure model is proper for the longitudinal impact. It is shown that with the influence of poisson effect, the longitudinal impact force is presented which reveals that the time history of the longitudinal impact force is not a smooth curve. Some parts of the curve are wavy and the extremums of the longitudinal impact force come later. It is shown that the propagation of the transient stress wave and velocity wave along the flexible bar during impact is also different. The influence of poisson effect is related with the width and length of the flexible bar, when the width of the flexible bar increases or the length of the flexible bar decrease, the influence of poisson effect becomes greater. The results prove that the technique is able to solve impact problem of flexible bar with influence of poisson effect. And it is able to identify the transient waves that travel along the flexible bar during impact.