热塑性聚合梯度材料及其结构的热黏弹性行为

In this project, thermoplastopolymetric graded material and its structures are taken as research objects, assuming that the short fiber and polymer is, respectively, elastic and viscoelastic materials, the viscoelastic character of two phases'interface is analyzed, a two-phase blend model is established and it can reflect the dynamic viscoelasticity of the thermoplastopolymetric graded material and the geometric relation of components. Considering the influence of viscoelastic and creep feature for the thermoplastopolymetric graded material in the defromation state, an isothermal and changed temperature constitutive relation for the thermoplastopolymetric graded material is established.Under the action of the alternating stress or strain,the thermoviscoelastic dynamic response for the structures of the thermoplastopolymetric graded material is analyzed, and explores and discusses the influence of the short fiber content,aspect ratio,geometric size and viscoelastic character of two phases' interface for the thermoplasto-polymetric graded material on the thermoviscoelastic behaviors;the expressions of physical related with dynamic thermoviscoelastic behavior are studied and the influence of energy dissipation on the mechanical properties of the structures for the thermoplastopolymetric graded material.This project will enrich and develop the thermoviscoelastic theory for the thermoplastopolymetric graded material and its structures, creep theory, reliability analysis and optimum design of the thermo- plastopolymetric graded structures, and it has great theoretical significance and engineering application value.

本项目以热塑性聚合梯度材料及其结构为研究对象，计组份材料短玻纤为弹性体和聚合物为黏弹性体，通过实验测定组份材料界面的黏结性能，建立能反映动态黏弹性与组份材料之间几何关系的两相共混模型。考虑在热环境下聚合物材料变形行为的黏弹性和蠕变特性，寻求热塑性聚合梯度材料等温和变温黏弹性本构关系。在交变应力或应变作用下，分析热塑性聚合梯度材料结构的热黏弹性行为，探讨短玻纤的含量、长径比、几何形态及两相界面黏结性能对热塑性聚合梯度材料结构的热黏弹性力学性能影响；研究与热黏弹性相关物理量的表达式和能耗对热塑性聚合梯度材料结构力学性能的影响，揭示与此相关的物理现象和本质，预测可能产生的后果，并通过数值模拟和实验对理论分析结果进行验证和评估，发现新现象。本项目将为热塑性聚合梯度材料及其结构的热黏弹性理论、蠕变理论、结构的安全评定和优化设计等提供理论依据，且具有重要的理论意义和工程应用价值。

本项目考虑热塑性聚合梯度材料及其结构，以含梯度界面短纤维增强复合材料为主要研究对象，计短纤维为弹性体和聚合物为黏弹性体，建立了该复合材料的热黏弹性三相共混微观模型，获得了有效预测该复合材料热黏弹性本构特性的细观方法。考虑在热环境下聚合物材料变形行为的黏弹性和蠕变特性，采用线弹簧损伤模型，研究了含梯度界面且具有界面微损伤热塑性聚合梯度材料结构的蠕变和松弛特性，及其与材料微观结构特性和环境温度之间的关系。在交变应力或应变作用下，分析了含界面损伤和梯度界面的热塑性聚合梯度材料结构的热黏弹性行为，包括储能模量、损耗模量和损耗因子的温度相关性和外载频率相关性，及与材料微观结构参数的内在关联。基于双参数纤维聚集模型，提出了以组份质量为参数的新型纤维聚集模型，对多孔热塑性聚合梯度材料结构的有效性能进行了预测，并讨论了短玻纤的含量和几何特征、孔隙、纤维聚集度及界面黏结性能对多孔热塑性聚合梯度材料结构的热黏弹性力学性能的影响，得到了各参数对其热黏弹性力学行为的影响规律。考虑短纤维和颗粒混合填充热塑性聚合材料，研究了增强相形式和含量对材料有效性能的影响。项目中的理论研究结果均通过数值模拟和实验进行了验证和评估。. 本项目的研究达到了预期目标，获得了较丰硕的研究成果，共发表学术论文25篇，其中SCI收录25篇次，EI收录7篇次；参加学术会议并作报告7人次；培养博士生1人和硕士生3人。