Non-Linear Buckling Analysis of Non-Prismatic Steel Columns Subjected to Axial Compression Loads

Abstract

This study investigates the effect of non-uniform cross-section on the behavior of steel columns subjected to axial compression load. A nonlinear finite element model using ANSYS 12.0 has been adopted to investigate the behavior of square and circular steel columns. The steel is assumed to behave as an elastic-plastic material with strain hardening in compression. The type of elements have been used to model the steel; SOLID45. The axial- load displacement curves and the deformation shapes were predicted. A parametric study on columns with square and circular section has been done. All the analyzed columns have the same value of cross-section volume for the column, yielding strength, and boundary conditions with different length of column. The results show that the behavior of non-prismatic column is always by the tapering ratio and the slenderness ratio on the elastic buckling. As the taper ratio increases, the elastic buckling load increases, in the main while the maximum ultimate load occurs in the (prismatic column) comparing with the non-prismatic column.

Keywords: Non-uniform cross-section, Steel columns, nonlinear finite element, Elastic buckling load.