ULTIMATE STRENGTH OF STEEL FRAMES WITH LATTICED GIRDERS

Abstract

This thesis presents a displacement fmite element model to study the nonlinear elasto-plastic behaviour of framed structures with latticed girder. The nonlinear inelastic response of the theoretical behavior of framed structures with latticed girder is predicted throughout the entire range of loading up to the point of the maximum carrying capacity. This study takes into consideration the instability effects caused by the axial force, geometric nonlinearity of columns, and the material nonlinearity. In this thesis presents all the previous published work in the field. Also the scope and objectives of the present study are outlined in detail. The load and boundary conditions are adopted to obtain the ultimate strength of trussed frames (in plane failure). Various trussed beams to columns bending stiffuess ratios, as well as various ratios of trussed beam to column height, have been studied. Furthermore, the effect of initial geometric imperfections with various mode shapes on the ultimate loads of these frames is also studied. The analysis was performed on single-bay trussed frames; two bays trussed frames and trussed frames with stepped columns. The analysis was carried out using the Ansys program. Several published cases were chosen in order to check the accuracy of using the Ansys program results.