TRANSIENT ANALYSIS OF THREE DIMENSIONAL SPACE FRAME

Abstract

In every days life, three dimensional structures are normally subjected to transient loading. Therefore, it is essential at the design stage itself to determine the transient response of the 'three dimensional structures under different types of excitations. In this dissertation work, a software has been developed using Finite Element Method to determine the transient response of the three dimensional structures in the elastic range. The spatial behaviour is described using beam elements having six degrees of freedom per node and the temporal behaviour is approximated using implicit schemes, Wilson 0 method and Newmark method. For fixing the time interval of analysis, the transient response of the cantilever and simply supported beams, discretised using different number of elements, have been studied. Here, the comparison has been made between the responses obtained by Wilson 0 and Newmark methods for Consistent and Lumped mass models. Then, for determining the applicability of program for the practical problem, a three-wheeler chasis frame has been analysed. The transient response of the three-wheeler chasis frame structure has been determined for Consistent and Lumped mass models. In both these cases the transient response obtained by Wilson 0 and Newmark methods has been compared. The study indicates that the Wilson e method requires too much reduction in the time interval At, for getting accurate results, while Newmark method gives accurate results at comparatively higher values of At.