Fatigue analysis of the polymerized vessel subjected to cyclic internal pressure and thermal loads

One polymerized vessel was subjected to cyclic internal pressure and thermal loads during the service, the crack, was found at cannula of lower temperature measurement nozzle. In order to explore the causes of cracking. the mechanical and thermal stresses of the structure were analyzed by the finite element method. The convective heat transfer between polymerized vessel and Jacket was analyzed numerically. The temperature distribution was obtained. The stresses of the structure subjected to internal pressure and thermal loads were calculated. Based on different working conditions. the maximum stress amplitude was calculated, and the fatigue life of polymerized vessel was evaluated by the S-N curves. The numerical simulation result agreed well with the actual fatigue life of the vessel.