ANALYTICAL MODELING OF HYDRAULICALLY EXPANDED TUBE-TO-TUBESHEET JOINTS

摘要

The loss of the initial tightness during service is one of the major causes of failure of tube-to-tubesheet joints. The initial residual contact pressure and its variation during the lifetime of the joint is among the parameters to blame. A reliable assessment of the initial contact pressure value requires accurate and rigorous modeling of the elasto-plastic behavior of the tube and the tubesheet during the expansion process. This paper deals with the development of a new analytical model used to accurately predict the residual contact pressure resulting from a hydraulic expansion process. It is based on the elastic perfectly plastic material behavior of the tube and the tubesheet and the interaction between them. The model results have been compared and validated with those of the more accurate numerical FEA models. Additional comparisons have been made with existing methods.