Structural optimization design of non-uniform stiffened cylindrical shells with geometric imperfection

Abstract

In order to improve the load-carrying capacity of stiffened cylindrical shell, a new type of non-uniform stiffened cylindrical shell is proposed. Different from the traditional stiffened cylindrical shells, the stiffeners of non-uniform stiffened cylindrical shells are non-uniformly arranged. Based on the nonlinear explicit dynamic method, the stability analysis of non-uniform stiffened cylindrical shells is carried out, and the load-carrying capacities of the perfect structure and the imperfection structure of shells are obtained. Without the reduction of the mass of the structure, the non-uniform stiffened cylindrical shell structure can reduce the stiffness at both ends of the shell and enhance the stiffness at the middle part of the shell to avoid the initial instability in the middle part of the shell structure. Therefore, the load-carrying capacity of thin-walled structure is improved. In addition, the non-uniform stiffened cylindrical shell structures exhibit better mechanical property in terms of resistance to geometric imperfection and lower imperfection sensitivity. Moreover, a new optimization framework for non-uniform stiffened cylindrical shells with low imperfection sensitivity is proposed. The practicability of the optimization framework and the applicability of the structures in engineering are tested by the illustrative examples.