地基沉降作用下埋地聚乙烯管强度失效的数值模拟

对聚乙烯(PE)管进行不同应变率下的拉伸试验,并采用率相关本构模型获得PE管的材料参数.利用Abaqus软件模拟了埋地PE管在地基沉降作用下的应力-应变行为,分析了PE管应力随沉降位移的变化情况,探讨了过渡段长度对PE管屈服应力的影响.结果表明:PE管的最大Mises应力随沉降位移的增加而增大,危险段发生在过渡段与沉降区或非沉降区的交界处;随着过渡段长度的增加,PE管屈服的沉降位移逐渐增大,在同等沉降位移条件下,长过渡段埋地PE管比短过渡段埋地PE管更安全.

Numerical Simulation of Strength Failure of Buried PolyethylenePipes under Foundation Settlement

Tensile tests at various strain rates were conducted on polyethylene(PE) specimens. The rate dependent constitutive model was applied to characterize the tensile properties of PE and the fitting material parameters of the PE were obtained. Based on the selected constitutive model and the obtained material parameters, Abaqus large scale finite element platform was used to simulate the mechanical response of buried PE pipeline under foundation settlement. Then, the variation of pipe stress with settlement displacement was analyzed and the relationship between transition length and PE pipeline yielding condition was discussed. The results show that the maximum Mises stress of PE pipelines increase with the increase of settlement displacement. The dangerous section occurs at the junction of the transition section and the settlement zone, or at the junction of the transition section and the non settling zone. According to the yield failure criteria, the maximum safe service settlement displacement of PE pipelines was discussed. It is found that with the increase of transition length, the settlement displacement of yielding pipelines increases. In other words, given the same settlement displacement, the buried pipeline with longer transition section is safer.