Incomplete reduced stiffness method for imperfection sensitivity of cylindrical shells

Cylindrical shells are commonly used in the industry structures, and they are prone to buckling under axial compression load. However, the practical critical loads are often lower than the theoretical value of buckling load due to the presence of imperfections. In this paper, an incomplete reduced stiffness method (iRSM) is proposed to perform the imperfection sensitivity analysis of cylindrical shells. In the iRSM, it is assumed that membrane stiffness components of the shell would be eroded at the critical buckling state, and a reduction function with two parameters is proposed to describe the mapping between membrane stiffness components and the geometric imperfections of the shell. Then, the buckling load of imperfect cylindrical shells can be obtained by solving the linear buckling problem of the reduced-stiffness system. For typical cylindrical shells, the reduction function is determined according to the measured imperfection and experimental results. By comparison with the experimental results and other conventional methods, it is demonstrated that the iRSM is a high accurate, slightly conservative and fast method to perform the imperfection sensitivity of cylindrical shells.