Dynamic buckling of imperfect cylindrical shells under axial compression and bending moment

The dynamic stability of circular metallic and laminated cylindrical shells is investigated. The cylinders are geometrically imperfect and subjected to axial compression or pure bending moment, These loads are suddenly applied with constant magnitude and finite or infinite duration, The finite element method is employed to generate dynamic responses and the equations of motion approach to determine dynamic critical loads. The effects of load duration and imperfection amplitude on critical loads are discussed, It is found that the dynamic critical loads decrease with increasing load duration and converge to those for the load case of infinite duration. The convergence rate is related to the fundamental frequency of the cylinder. In addition, both the static and dynamic critical loads decrease with increasing imperfection amplitude.