Elastic–Plastic Investigation of Shipboard High-Energy Pipes Under Shock Loading

To evaluate the shock safety of shipboard high-energy pipes subjected to underwater explosion when the power system is operating, simulation model of the high-energy pipes combined with the corresponding double-layer isolation system is established using ABAQUS, based on the elastic–plastic constitutive relation of pipe material under high temperature and high strain rate. Strain and stress response of the working pipes under tri-axial shock loads is obtained by the time-domain algorithm, and the allowable stress suitable for key high-energy pipes in transient condition is derived. The results indicates that, plastic strain appears in the pipes under shock loading, and a high risk arises in the elbows and tee joints when the shock stress accumulated with the operating stress, since the bending and twisting deformation is coupled in these regions, leading to the coexisting of tensile and shear stress. Furthermore, anti-shock design is employed in the isolation system, and the shock safety can be achieved by the using of metal bellows and flexible clamps on high-energy pipes.