Failure modes of pressure vessel components and their consideration in analyses

Metallic pressure vessel components such as dished ends show different modes of failure depending upon the geometrical and loading conditions. These are mainly gross plastic deformation under static load, loss of stability (buckling), fatigue crack initiation at highly stressed locations under cyclic loading (especially in the low cycle regime), progressive plastic deformation (ratcheting) and creep at high temperatures. Existing codes are mostly used to determine necessary wall thickness (design by rule) based on the static load-carrying capacity. Guidelines for other failure modes are given in a more or less general way for complex structures. In this article it is shown that all the failure modes mentioned can be estimated by carrying out linear and non-linear finite elements analyses. The possibility of using the finite elements method as a basis for design by rule and design by analysis is discussed.