Calculation of a lower bound ratchet limit part 2 – Application to a pipe intersection with dissimilar material join

In an accompanying paper in this issue a lower bound method based on Melan's theorem was derived and implemented into the Linear Matching Method ratchet analysis procedure. This paper presents a ratchet analysis of a pipe intersection subject to cyclic thermo-mechanical loading using the proposed numerical technique. This work is intended to demonstrate the applicability of the lower bound method to a structure commonly seen in industry and also to better understand the behaviour of this component when subjected to cyclic loading. The pipe intersection considered here has multiple materials with temperature dependent properties. Verification of the results is given via full elastic-plastic analysis in Abaqus.

► The Linear Matching Method is used to analyse a pipe intersection.
► A constant internal pressure, cyclic thermal and cyclic bending is considered.
► Ratchet interaction diagrams are created and failure mechanisms explored.
► Verification by elastic-plastic step by step FEA is provided.