SHEAR EFFECT ON THE ELASTIC CRITICAL BUCKLING LOAD OF NON-PRISMATIC COLUMNS

Abstract

An analytical solution for determining the elastic critical buckling load for tapered members including shear effect are studied in this paper with different support conditions. The calculations are based on the exact stability function including shear effect for uniformly tapered beam-column having laced or battened build-up structural members, and approximate stability functions for a wide range of non-prismatic member including shear effect using the finite difference method. The modified stability functions for nonlinear tapered member including shear effect is also obtained in this paper by using the stability functions for a linearly tapered member in the form of modified shape factor ( ) and modified taper ratio (ū). Buckling of tapered columns is studied in many numerical examples. The results show that, inclusion the effect of shear deformation in the calculation of critical load can result in a significant reduction in the value of the critical load for both prismatic and non-prismatic laced columns. The effect of the shear is depending on the value of shear parameter µ2 and tapering ratio u. The average ratio of reduction is (63.315%) and (64.7 to 65) % for prismatic and non-prismatic laced columns respectively. In the structures having prismatic and non-prismatic solid columns, the effect of shear deformation can have a significant effect with the range of (32.42 to 56.78) % on the value of critical load.