APPLICATION OF DYNAMIC FINITE ELEMENTS IN ANALYIS OF FRAME STRUCTURES UNDER IMPACT LOADING

Abstract

The application of the Dynamic Finite Element (DFE) to the analysis of building frame structures at impact load is considered. The DFE stiffness and inertia matrices are constructed on the base of analytical (exact) solutions of vibration equations of a bar. At impact load research the hypothesis that local deformations near contact zone of colliding bodies are related with the contact force by static dependencies, and also the general deformations of a building structure, which are determined by vibration theory methods, are taken into account. The influence of impact load parameters on frame system response is studied on the example of a single beam, subjected to tension (compression) and bending loads. The impact load was modelled as a sine curve with various frequency, and also in the form of equivalent impulse. It is shown, that at the increase of the impact load frequency the response character remains unchanged, however, its amplitude decreases. The efficiency of DFE application in impact problems is shown by comparison with existing analytical solutions, as well as with the analysis results, obtained with usage of classical finite element with polynomial shape functions.