Comparison of Plastic Collapse Load of Isolated Piping Part and Pipe Run

Abstract

The analysis of plastic collapse may be used in the fitness-for-service analysis of piping parts. Typically, such an analysis is performed by first determining the loads on the part in question by piping analysis, and then applying the load or load combination to an isolated elastic-plastic model of the part to obtain the collapse load. Plastic load redistribution that would occur if a plastic collapse analysis of the entire pipe run was performed is not considered in the common analysis approach. This paper compares the results of pipe run and piping part plastic collapse analyses for a typical illustrative example under various loading conditions.