短纤维橡胶复合材料强度的理论研究I 纵向拉伸强度的理论预测

首次在较宽的纤维用量和纤维长度范围内, 研究了短纤维橡胶复合材料的拉伸强度规律, 并基于Cox 剪滞法和复合材料的结构特点, 提出了一种新的混合定律模式, 对复合材料的纵向拉伸强度进行了理论预测。结果表明, 新的模型包含结构因素较全面, 理论计算值与实验值符合较好。此外, 探讨了复合材料的拉伸破坏机理, 认为复合材料的拉伸破坏主要由界面控制, 在复合材料中存在着界面剪切应力集中和纤维拉伸应力集中之间相互竞争增长的过程, 但前者的增长制约着后者的增长。本文是短纤维橡胶复合材料强度理论预测的第一部分。 

STUDY ON THE THEORY OF STRENGTH OF SHORT FIBER/RUBBER COMPOSITES I PREDICTION OF LONGITUDINAL TENSILE STRENGTH

The law of tensile strength of short fiber/rubber composites(SFRCs) was studied for the first time among a wide range of fiber volume and length. Based on the Cox shear lag and characters of SFRC, a new mixture law was put forward and the longitudinal tensile strengths of SFRCs were theoretically predicted.The results show that the new model includes more comprehensive structure factors and predicted values can well suit experimental values. In addition, the mechanism of tensile fracture of SFRCs was investigated; it was thought that fracture of SFRCs was controlled by the interface between fibers and matrix and there existed a competitive course between the increase of interfacial shear stress and increase of tensile stress on the fibers, where the former restricted the latter.