Abstract: In ideal manufacture of multilayer wrapped high pressure vessels, pre-stresses would be induced at the cylinders. But if the manufacture is not so accurate, interlayer clearances would exist and the pre-stresses cannot be guaranteed. In this paper, expressions for the stresses in multilayer wrapped high pressure vessels under pressure loading with or without pre-stresses were derived. Numerical simulations were conducted for verification. It is found that the analytic results are in good agreement with the numerical simulations and both indicate that application of pre-stresses can effectively improve the elastic stress distribution at the cylinder and increase the pressure-bearing capacity of the cylinder in the elastic stage. In the whole yielding stage, however, the limit-pressure of the cylinder only depends the thickness and materials of the inner cylinder and layers and is not affected by the pre-stresses. In addition, both analytic and numerical results also found the limit-pressure of the cylinder is not affected by the interlayer clearances.

Key words: multilayer wrapped, high pressure vessel, limit load, pre-stress, interlayer clearance