Torsional Buckling Analysis of a Bar Member

Abstract

During buckling of column, it is assumed that the column would buckle as the cross section bends in the plane of symmetry. But in some problems of buckling failures of column, it would be either due to twisting or due to combined effect of bending and twisting. Such a combined effect of bending and twisting in a structure is known as torsional buckling. In the present work, a thin-walled bar of cross section (b × t) with the length ‘l’ is studied by applying uniform axial compression. The differential equation for the deflection curve and the differential equation for torsional buckling are presented. The expressions for total moment, torque and torque per unit length are derived and finally the expressions for the critical stresses and critical load for torsional buckling failure are derived. A numerical example is solved. The critical stress and critical load are calculated.KeywordsBucklingTorsional bucklingCritical stressCritical load