裂纹深度比对聚乙烯管力学性能影响的研究及损伤模

Effect of Crack Depth Ratio on Mechanical Properties of Polyethylene Pipes and Damage Modeling

以高密度聚乙烯(HDPE)管材为研究对象,提出了两种改进的静态损伤模型;通过对不同寿命分数(裂纹深度比)的试样进行单轴拉伸试验,并将得到的屈服应力作为损伤模型中的剩余屈服应力,获得了聚乙烯(PE)管的损伤曲线。通过损伤曲线,确定了HDPE管道在工程实际使用过程中的三个阶段,以及临界寿命分数约为40.2%。结果表明,第二阶段应是维护人员从事维护的主要阶段,以保证HDPE管道的安全运行。

In this paper, with high density polyethylene （HDPE） pipe as research object, two modified static damage models were suggested. The damage curves were got by the uniaxial tensile tests of the samples with different crack depth ratios, and the yield stress was used as residual yield stress in the damage model. Through the damage curves, the three stages of HDPE pipes in the actual use of the project were determined, and the critical life fraction （crack depth） was about 40. 2%. The results show that the second stage is considered as the primary stage for the staff to engage the maintenance to ensure the safe operation of HDPE pipeline.