Testing And Analysis Of Elastic-plastic PinnedBeams Under Impulsive Loading

An analytical model for the analysis of beams with pinned ends is presented. The deflection shape accounts for the stretching (membrane) force. The elasticplastic beam is analysed under impulsive loading using the equation of motion derived by the virtual work principle. Elastic and plastic strain rate effects are considered as viscous damping. An apparatus to test beam specimens subjected to impulsive loading is presented. It comprises a moving carriage tended by springs. Mild steel specimens 400mm long and 10 to 20mm thick softened by annealing were tested. The comparisons of the analytical and experimental results show a good agreement. This model is also compared with the results of rigid-segment models. The comparisons show that it is important to consider elastic deformations in the analysis especially in cases of low levels of impulse producing permanent midspan deflections less than the thickness of the specimens.