为了更好地理解PSP(plastic pipes reinforced by cross helically wound steel wires)在外压作用下的长时力学性能,提出一个PSP临界蠕变失稳压力的分析模型.将PSP简化为内高密度聚乙烯HDPE(highdensity polyethylene)层、内钢丝-粘结树脂层、外钢丝-粘结树脂层和外HDPE层的4层结构,基于PSP各层的线粘弹性本构关系,应用扁壳理论,对应不同时间可以得到PSP相应的临界失稳载荷;设计搭建外压试验装置和真空试验装置,得到恒定外压作用下PSP的临界失稳时间,试验测试结果和理论计算结果吻合,所建模型可用于预测PSP临界蠕变失稳压力.最后分析PSP内径、钢丝缠绕角、钢丝根数、钢丝-粘结树脂层厚度、HDPE层厚度等设计参数与持久临界压力的关系,提出提高PSP临界蠕变失稳压力的措施.%To study the long-term mechanical properties of PSP under external pressure, a four-layer creep analytical model was proposed.The model included an inner high density polyethylene (HDPE) layer, an inner steel wires layer, an outer steel wires layer and an outer HDPE layer.Based on the linear viscoelastic constitutive equations of the four layers, the critical buckling pressure of the PSP at different buckling time was deduced according to the shallow shell theory.To carry out the parallel experiments, the external pressure experimental device and a vacuum experimental equipment were designed.Good agreement between the theoretical results and the experimental data was observed.It shows that the presented model can be used to predict the critical creep buckling pressure of the PSP.The design parameters were investigated and the measures to increase the critical buckling pressure of the PSP were proposed.
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