刚性微粒填充高聚物的宏观本构关系

用微观力学和统计方法研究了含损伤过程的刚性粒子填充高聚物的非线性本构关系．在材料的变形过程中，粒子与基体间界面的开裂引发微孔洞的成核与长大，这虽然弱化了材料的宏观力学性能，但是带来了宏观本构的非线性效应，这为材料的增韧奠定了基础．该文分析了刚性粒子对材料的强化作用和微孔洞演化对材料的弱化作用，以及这两种竞争机制的耦合效应对宏观本构关系的影响，并从理论上给出了界面强度，粒径分散度，平均粒径等参量对材料宏观力学行为影响的定量分析结果．

THE MACROSCOPIC CONSTITUTIVE RELATION OF PARTICULATE REINFORCED POLYMER

By means of micromechanics and statistical method,the non linear consitutive relation of particulate reinforced polymer is studied.In the deformation process,the debonding damage of the particle matrix interface may occur and will lead to microvoid nucleation.The statistical behavior of microvoids' nucleation and evolution are investigated by using Eshelby's equivalent inclusion method and Mori Tanaka's mean stress field concept.The stiffness of the material will decrease due to microvoid evolution and the macroscopic constitutive relation will gradually be changed from linear one to nonlinear one.Such a phenomenon,on the other hand,shows that the material may be toughened.The reinforcing effect due to intact rigid particles and the weakening effect due to microvoids evolution,as well as their coupling effect on the macroscopic constitutive relations are studied in this paper.The influences of interface strength particle size dispersity,and average particle size on the macroscopic constitutive relation are also discussed.The research results indicate that higher interface strength,lower particle size dispersity,and smaller average particle size will be effective for reinforcing and toughening polymer materials under the condition that matrix strength is higher than interface strength.