Dynamic Buckling of Bars under Step Load Based on Semi-Analytic Method

Dynamic buckling of bars under step load was studied by considering the stress wave effect. Straight bars without axial inertia were taken as an example when deformation was small. The buckling solution satisfying the boundary conditions was given by the semi-analytic method. The buckling solution was substituted to the dynamic buckling governing equations. The unified expression of dynamic buckling critical load was obtained by discussing the character of the solution. The dynamic buckling critical load was obtained by calculating the value of when the stress wave propagated to the critical length . The value of dynamic buckling load was 2.5 times the one’s of static buckling load with corresponding equivalent length.