关键词: 聚乙烯, 燃气管道, 点载荷, DFDI模型, 管道损伤

Abstract: The elasticity and yield parameters of PE were determined through a uniaxial tensile experiment. A pipe-soil finite element model under a point load was established to study the point-loading mechanical response of buried PE gas pipes， and the effects of point-loading dimension， pipe internal pressure， and pipe diameter were analyzed. Based on the DFDI （ductile failure damage indicator） model and combined with the finite element simulation results， quantitative damage calculations were carried out for PE pipes under a point load. The results indicated that the point load increased the pipe damage when compared to the damage results of the pipe without a point load. The pipe damage shows a great change with a variation of the internal pressure of the pipe. There is little effect on the PE pipe damage with a small change in the pipe diameter， and the damage values under each pipe diameter are relatively close to each other.

Key words: polyethylene, gas piping, point load, ductile failure damage indicator model, pipe damage