NUMERICAL STUDIES ON NON-LINEAR BEHAVIOR OF COMPOSITE STEEL TUBES USING ABAQUS V6.10-1*

Abstract

In steel and concrete composite construction, the two materials are integrated in structural members to combine the advantages of both materials steel has high strength and ductility and facilitates connections with steel girders and braces in a steel framing system. Concrete is economical, durable and fire resistant. In composite columns, steel tube confines the concrete core leading to an increase in both strength and ductility of the concrete. The concrete core restricts inward local buckling of steel tube. composite columns have been shown to shown to have high strength, stiffness and ductility. As little data is available to justify the structural response, accurate Non-linear static and dynamic computational formulations are required for developing rational system response factors. For developing rational system response factors. Non-linear FEM analysis is performed to quantify demand, optimize design among other purposes. In this dissertation, ABAQUS 6.10-1 and Hyper Mesh is used to study non-linear behavior of composite tubes. At the outset, Validation for the work done by previous researchers(G.Giakoumelias, D.Lam/ Journal of Constructional Steel Research 60(2004)1049-1068) is carried out using nonlinear FEM and is further extendented for experimental work done at the Department of Civil Engineering., R & D laboratory of Ghousia College of Engineering, Ramanagara. Experiments are carried out on columns for different tube thickness, diameter and length, obtained experimental values of ultimate load is compared with EC-4 including ABAQUS results. Frequency in Hz and time period in Sec are also evaluated for different tube sizes, lengths and thickness.