基于非牛顿流体的聚乙烯材料介观蠕变机制研究  

Research on mesoscopic creep mechanism of polyethylene based on non-Newtonian fluid

作　　者：刘铭[1] 徐献忠[1] 刘梦云 李晨阳 LIU Ming;XU Xianzhong;LIU Mengyun;LI Chenyang(School of Mechanics and Safety Engineering,Zhengzhou University,Zhengzhou 450001,China)

机构地区：[1]郑州大学力学与安全工程学院,郑州450001

出　　处：《功能材料》2021年第10期10092-10097,共6页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(10972202)。

摘　　要：基于非牛顿流体Ostwald-de Waele方程和介观体系,提出了一种可用于分析聚乙烯材料蠕变特性的研究方法,探讨了聚乙烯材料的蠕变机制并对材料的微观形貌、力学性能和亲水性等进行了测试表征,验证了该研究方法的可行性。同时,利用稳态蠕变本构方程与幂律流体的一致性对粘弹性材料进行了力学分析。结果表明,模型参数与非牛顿流体系数具有相似的物理意义,聚乙烯材料蠕变的主要变形机制为界面滑移产生的粘性变形,而应力松弛则为界面滑移、粘滞力和单元弹性的共同作用。使用基于稳态蠕变方程的应力松弛模型,对聚乙烯材料的应力松弛行为进行了分析,结合材料蠕变机制,提出了聚乙烯材料的介观松弛机制。A method is proposed to analyze the creep characteristics of polyethylene based on non-Newtonian fluids with Ostwald-de Waele equation and mesoscopic system.The creep mechanism of polymer materials is discussed,and the micro morphology,mechanical properties and hydrophilicity of the materials are characterized to verify the feasibility of the research method.Meanwhile,the mechanical analysis of viscoelastic material is carried out and the consistency between the steady-state creep constitutive equation and the non-Newtonian fluid is shown that the model parameters have similar physical meanings to the coefficients of non-Newtonian fluids.The creep mechanism of polyethylene belongs to the viscous deformation con-trolled by the interface slip,while the stress relaxation is controlled by the combination of viscous force,interface slip-ping and element elasticity.The stress relaxation behavior of polyethylene is analyzed by using the stress relaxation model and combining the creep mechanisms of the materials.The polyethylene mesoscopic creep and relaxation mechanism is proposed.

关 键 词：非牛顿流体 聚乙烯材料 介观 蠕变机理 应力松弛 

分 类 号：O344.6[理学—固体力学] O373[理学—力学]