A three-dimensional analytical solution for sandwich pipe systems under linearly varying external pressures

•An 3D analytical model for sandwich pipe systems has been proposed.•Our predictions are agreement with the results of FEM.•Our solution provides a benchmark for numerical and approximate solutions

A three-dimensional analytical model is presented to calculate the stress and deformation of a sandwich pipe (SP) system subjected to linearly varying external pressures. Based on a stress function method, an analytical solution for a thick-walled pipe was researched, and then an analytical solution for a SP system was obtained according to the boundary and continuity conditions of stress and displacement. Furthermore, the analytical solution of a SP system was verified by comparing with finite element method (FEM). The results indicate that the stresses from present method (PM) are in a good agreement with that from FEM. Finally, our researches provide a benchmark for approximate or numerical solutions, and are beneficial to evaluate the safety and integrality of SP systems.