热塑性聚合物材料的湿-热-力耦合循环本构关系研究

项目名称： 热塑性聚合物材料的湿-热-力耦合循环本构关系研究

项目编号： No.11272269

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 康国政

作者单位： 西南交通大学

项目金额： 90万元

中文摘要： 高性能聚合物材料已经越来越多地应用于承载结构领域，疲劳失效是聚合物材料结构构件失效的主要模式，而材料的循环本构关系是结构构件疲劳失效分析和可靠性评价的基础。本项目针对聚合物材料湿热环境下的非比例多轴循环本构关系研究方面的不足，开展如下系统的实验和理论研究：首先通过室温常湿、变温常湿和变温变湿条件下系统的单轴和非比例多轴(拉-扭组合)循环变形实验研究，揭示聚合物材料的循环变形特征和内部热效应形成机制以及湿热效应与循环变形之间的耦合作用；然后在实验揭示的演化规律基础上，基于不可逆热力学和小变形连续介质力学框架，建立聚合物材料热-力和湿-热-力耦合的循环本构模型。湿-热-力耦合循环本构模型的建立是材料循环本构关系研究方面的一个重大突破，具有重要的科学意义；同时，研究成果可直接应用于聚合物构件湿热环境下的疲劳寿命预测和结构可靠性评估中，解决迫切的工程需求，从而具有较高的工程应用价值。

中文关键词： 聚合物材料；本构关系；多场耦合；循环载荷；湿热效应

英文摘要： High-performanced thermoplastic polymers have beening used in the structure components subjected to cyclic loading, and fatigue failure is a main failure mode for these components. It is extremely necessary to study the fatigue behavior of thermoplastic polymers in order to ensure the safty and reliability of such structures. However, reasonable cyclic constitutive model is a key issue in the study of fatigue failure. To overcome the shortcomings in the study on the non-proportional multiaxial cyclic constitutive model of the polymers with the hygrothermal effect, this project will perform detailed experimental and theoretical research on such topics. At first, the uniaxial and nonproportional multiaxial (combined tension-torsion) cyclic deformations of three kinds of thermoplastic polymers are observed under the conditions of room-temperature and constant humidity, varied temperature and constant humidity, and varied temperature and humidity. The effects of humidity and temperature on the cyclic deformation of the polymers are addressed during the uniaxial and nonproportional multiaxial cyclic loading; and the internal heating mechanism of the polymer during the cyclic deformation and the interaction between the internal heating and cyclic deformation are deduced.Then, based on the results obtained from the exp

英文关键词： Polymer；Constitutive model；Coupled multifields；Cyclic；Hygrothermal effect