Dynamic buckling of thin cylindrical shells under axial impact

The dynamic buckling of thin isotropic thermoviscoplastic cylindrical shells compressed with a uniform axial velocity prescribed at the end faces is investigated analytically and numerically. In the first part of the paper, the stressed/deformed state of a shell is assumed to have buckled if infinitesimal perturbations superimposed upon it grow. Cubic algebraic equations are derived for both the initial growth rate of the perturbation and its wavenumber. The wavenumber corresponding to the maximum initial growth rate of a perturbation introduced at an axial strain of 0.1 is taken to determine the buckling mode. The computed buckling modes are found to match well with those listed in the available experimental data. A thermoviscoplastic constitutive relation is used to delineate the influence of material parameters on the buckling behavior. In the second part of the paper, the finite element method is used to analyze the collapse of an imperfect circular cylindrical tube with axial velocity prescribed at one of its flat end faces with the other end face kept fixed. The influence of initial randomly located imperfections on the buckling behavior is investigated and discussed.