Deflection analysis of bisteel I - section beams with elastic - perfectly plastic behaviour of THE Web

Abstract

Elastic - plastic deflection analysis of simple bisteel I - section subjected by uniformly distributed quasistatic load is considered in this paper. The bisteel beam presents a composition of higher - strength steel inclusions for the flanges in the region of maximum stresses and of lower - strength steel for remaining volume of the beam. The main aim of the present paper is deflection analysis of bisteel I - section beams with elastic - perfectly plastic behaviour of web. The variation of the strength ratio of the both steels and the variation of the length of inclusion leads to different distributions of plastic regions in the HBB. By fixing the depth of maximal plastic penetration in the web, while the flanges remain pure elastic, explicit expression of the plastic boundaries is presented. According to the evaluation of plastic penetration in the web, the semi analytical deflection analysis model has been developed. Here the curvature, slope and deflection are the deflection parameters under consideration. Using the proposed semi analytical deflection analysis model, the influence of different material properties and plastic penetration in the web are investigated. The proposed semi analytical model has been also tested numerically by the finite element method. The ANSYS code and tetrahedral elements have been used for these purposes.