Studies On Dynamic Buckling Of Bars Under Axial Impact

Bars which are always used as basic element in engineering are widely applied in many fields such as architecture, machine, aerospace engineering and transport etc., its dynamic buckling problem is one of the active subjects in the filed of solid mechanics, and drew most researcher much attention. The method of solving the problems are different, the final results are also different. In this paper, several aspects are studied in the following:1. The present researches on the dynamic buckling of bars are simply generalized, and the main methods and conclusions are summarized.2. Dynamic buckling of bars under step load was studied by considering the stress wave effect. Straight bars without axial inertia and shear effect were taken as an example when deformation was small. Buckling mode equation satisfying the boundary conditions is given, and was substituted to the dynamic buckling governing equation. The expression of dynamic buckling critical load is obtained, and the limit of xâ†'lcr was calculated. Then the dynamic buckling critical load is obtained, its magnitude is2.5times as much as the static buckling load with corresponding equivalent length.3. Dynamic buckling of bars under step load was studied by considering the stress wave effect. Straight bars with shear effect were taken as an example when deformation was small. The dynamic buckling critical load is obtained. The influence of shear effect on dynamic buckling critical load was analyzed. The influence of cross-sectional area and ratio of width to height on dynamic buckling are analyzed based on calculating by MATLAB.4. Dynamic buckling of an elastic bar subjected to axial impact by a rigid body was studied by considering the stress wave effect. The dynamic buckling critical load is obtained. The influence of ratio of mass, impact mass and critical length on dynamic buckling critical load is analyzed based on calculating by MATLAB.