静荷载作用下聚乙烯管材的粘弹塑性模型及流线扩散数值分析  

Viscoelasticity and Viscoplasticity Analysis of Polyethylene Pipes under Static Loads via Streamline Diffusion Method

作　　者：李月丽 袁盛峰 LI Yue-li;YUAN Sheng-feng(School of Mechanical Engineering,Tongling University,Hefei 244061,Anhui,China)

机构地区：[1]铜陵学院机械工程学院,安徽合肥244061

出　　处：《贵阳学院学报（自然科学版）》2020年第2期5-10,共6页Journal of Guiyang University：Natural Sciences

摘　　要：聚乙烯管材在工程应用中占有极大比重,而在长期服役过程中管材常受静荷载作用。故而研究其粘弹性、粘塑性等本质力学行为对掌握聚乙烯管材的变形与应力规律进而指导工程实践具有重要意义。文章通过对聚乙烯材料及聚乙烯管材的室内应力松弛试验,找到了适合聚乙烯管材的Maxwell模型。再利用流线扩散有限元方法对聚乙烯管材静荷载作用下的粘弹塑性力学行为进行分析,同时利用Prony级数对其进行对比计算以验证SDM分析的准确性。结果表明:在静荷载作用下应力在开始阶段增大,到达一定值后开始随时间增加逐渐减小。而SDM分析值与Prony级数计算值相差无几,该方法及模型可用于聚乙烯管材的应力及变形分析。Polyethylene pipe accounts for a large proportion in engineering applications,and they are often subjected to static loads during the long-term service.Therefore,it is of great significance to study the essential mechanical behaviors of polyethylene pipes such as viscoelasticity and viscoplasticity for determining their strain and stress regularity and instructing engineering practice.Via the laboratory stress relaxation test of polyethylene material and polyethylene pipe,the Maxwell model was found.Then the viscoelastic and viscoplastic behavior of polyethylene pipes under static load is analyzed by Streamline Diffusion Method(SDM).Simultaneously,the model was calculated via the Prony series to verify the accuracy of the SDM.The results demonstrated that the stress increases at the initial stage and gradually decreases with time development after reaching a certain value.Moreover,the SDM analysis value is consistent with the calculation of the Prony series.Therefore,the method and model can be used for stress and strain analysis of polyethylene pipes.

关 键 词：管材 聚乙烯 粘弹塑性 流线扩散有限元 

分 类 号：TQ325.12[化学工程—合成树脂塑料工业] TQ320.724