ANALYSIS OF FREE AND FORCED VIBRATIONS IN THE TWO-STOREY BUILDING FRAME WITH CRACKS

Abstract

This paper aims to analyze the free and forced vibrations of the two-storey building frame with cracks. The two-storey frame system with cracks is modelled when many constituent parameters existed such as crack depth, crack location, flexural stiffness and elastic force which were involved by a nonlinear function. In addition, in analysis of forced vibrations, the effect of random external loads is carried out to find probability characteristics of displacements. The resulting of structural responses is the mean square value of the displacement, the natural frequency of vibrations, and the probability density function of displacements. It can be found that when cracks appear in the middle of the columns, they would need to be considered most carefully because this problem will make the structure to become very dangerous during its existence. The results obtained in this paper can be used in the test calculation taking into account the influence of many parameters when analyzing responses of the structural system.