Pressure Cycle Life Prediction of Type III FRP Pressure Vessel

Abstract

A design diagram to predict cycle life to leak is proposed for Type III composite pressure vessels taking account of mean stress shift caused by autofrettage. We have conducted pressure cycle tests by employing Type III vessels of 2. 0 L specially designed to realize various combinations of stress range and the maximum stress, which are exactly evaluated by means of the finite element simulations. Revealing low advantage of autofrettage for high cycle fatigue life, we derive fatigue life prediction diagram in terms of stress range and the maximum stress of A6061-T6 liner over 100000 cycles life.