Elastic-plastic finite element analysis of high pressure components in low density polyethylene plants

摘要

Elastic-plastic finite element analysis (FEA) is used in high pressure component design as a powerful tool to determine the load bearing capacity of pressure retaining parts. The modes of failure that can be analysed include gross plasticdeformation or plastic collapse, ratcheting, creep and plastic instability.Apart from static analysis, the method offers itself for investigation of different effects where material yielding occurs; such as autofrettage, elastic-plastic gasket behaviour and elastic-plastic shrink ring design.In this paper, applications of the elastic-plastic PEA for mechanical components in Low Density Polyethylene (LDPE) plants will be presented. It will become apparent, that even for well known parts the elastic-plastic approach yields new findings incomparison to conventional analysis methods. For this purpose, three example analyses have been carried out, including a flange connection, a shrink ring and an autofrettage simulation.