Elbow stress indices using finite element analysis

Abstract

Existing ASME Code provisions allow for an experimentally determined collapse load. This collapse (limit) load can then be used in the Code equation defining stress indices to obtain a stress index experimentally. This paper describes a research project to investigate the use of inelastic finite element analysis, rather than experiments, to obtain the collapse load. An example is given for a 2-in., schedule 40, long radius, 90°, stainless steel elbow with 10-in.-long straight pipes on each end. A B 2 index is found using this approach which is nearly 50% lower than the one obtained using the Code equation for B 2.