Element Bearing Ratio Based Shakedown Analysis for Branch Pipe

Shakedown analysis is important for branch pipe because it is often damaged under various water pressure. In this paper, an element bearing ratio (EBR) based shakedown analysis method is employed for shakedown analysis of branch pipe. The EBR is used to replace the stress term in classical optimization problem in the procedure, and series of residual EBR fields can be generated by the D-value of the elastic-plastic EBR fields and the elastic EBR fields at every incremental loading step. The shakedown load is determined by performing an incremental non-linear static analysis when the yield criterion is arrived either by the elastic-plastic EBR fields or residual EBR fields. By introducing the EBR, the proposed procedure can be easily used to shakedown analysis of branch pipe with multi-material and complicated configuration. Numerical examples validate the method and demonstrate its performance.