基于纤维束/环氧树脂复合材料试验的单向层合板横向拉伸强度预测方法

实验研究表明，纤维束/环氧树脂复合材料试件的横向拉伸强度与工程上常用的单向层合板横向拉伸强度在趋势上具有很好的相关性，但是数值上存在一定差距。本文使用两种碳纤维和两种环氧树脂制备了三种纤维束/环氧树脂复合材料和单向层合板，并分别测量了纤维束/环氧树脂复合材料和单向层合板的横向拉伸强度，以及环氧基体的拉伸强度。在实验基础上，应用Griffith断裂强度理论建立了纤维束/环氧树脂复合材料和单向层合板的横向拉伸强度的关系模型，通过两种复合材料实验的结果拟合了该模型中的参数。利用第三种复合材料实验进行校验，发现该模型预测的单向层合板横向拉伸强度与实测强度之间达到很好的一致性，相对偏差为9%。采用本文提出的方法，可以用较为简单的纤维束/环氧树脂复合材料和环氧基体拉伸试验预测单向层合板的横向拉伸强度。

A prediction method of transverse tensile strength of unidirectional laminates based on test of fiber bundle/epoxy resin composites

Experimental study shows that the transverse tensile strength of fiber bundle/epoxy resin composites specimens has a good correlation with the transverse tensile strength of unidirectional laminate specimens. However, there is a discrepancy in values obtained using the two testing methods. In this paper, three types of fiber bundle/epoxy resin composites and unidirectional laminates were prepared using two kinds of carbon fibers and epoxy resins. Based on the measured transverse tensile strength of fiber bundle/epoxy resin composites and unidirectional laminates, as well as the tensile strength of epoxy matrices, a strength model was established to bridge the transverse tensile strength of fiber bundle/epoxy resin composite and unidirectional laminate. The parameters in the model were fitted according to the experimental results of two types of fiber bundle/epoxy resin composites and unidirectional laminates. Then the model was verified using the third type of fiber bundle/epoxy resin composite and unidirectional laminate. It is found that the predicted transverse tensile strength of the unidirectional laminate agrees well with the measured value, with relative deviation of 9%. Therefore, the proposed method can be employed to predict the transverse tensile strength of unidirectional laminates with simple tensile tests of fiber bundle/epoxy resin composites and epoxy matrices.