Dynamic plastic buckling of circular cylindrical shells under axial impact

In the present paper, experimental and theoretical studies on dynamic plastic buckling of circular cylindrical shells under axial impact are carried out. Experiments of circular cylindrical shells under axial impact are finished on Hopkinson bar and drop hammer apparatus. From the experiments, the first critical velocity corresponding to the axisymmetric bucking mode and the second critical velocity corresponding to the non-axisymmetric buckling mode are determined. Two different kinds of non-axis-symmetric buckling modes oval-shaped and triangle shaped are founded. The buckling modes under two loading manners, viz. by small mass but high velocity and large mass with low velocity using Hopkinson bar and drop hammer, are different. Their critical energies are also discussed. The buckling mode considering axial and circumferential coordinate is assumed to analyze the plastic buckling problem theoretically. By using the analysis of amplification functions method, the critical velocities corresponding to axisymmetric or non-axisymmetric buckling modes are obtained. The relationships between critical velocities and radius-to-thickness ratios are also discussed.