Rational Stress Limits and Load Factors for Finite Element Analyses in Pipeline Applications Part I – Linear Elastic Stress Limit Development

ABSTRACT:

In this paper, a rational stress limit based on the von Mises equivalent stress is established for pipelines subjected to internal pressure. This stress limit is based on the ASME pipeline Code’s design margin for the service and location of the installation. These Codes are recognized by 49 CRF192.

Both capped-end and open end conditions are considered. The single value of stress limits can be derived by classical hand calculations for use in assessing the results of a finite element analysis (FEA).

Two application examples are presented showing studies done with ABAQUS, a commercial FEA software. A stress limit was first found using classical hand calculations and verified by a simple finite element model. The linearized stresses at some critical locations were then compared to the established stress limit, and multiples, for the assessments of membrane, membrane plus bending, etc. stresses.

This paper is not intended to revise or replace any provision of ASME B31.8. Instead, it provides a rational stress limit that may be used in the assessment of detailed FEA analyses of pipelines and the associated components.

Lin, B. and Biel, R.C., “Rational Stress Limits and Load Factors for Finite Element Analyses in Pipeline Applications Part I – Linear Elastic Stress Limit Development”, Proceedings of IPC 2010 (Paper No. IPC2010-31132), the 8th International Pipeline Conference, September 27 – October 1, 2010, Calgary, Alberta, Canada.