三维四向编织复合材料体胞模型的修正

基于弹性理论建立了三维四向编织复合材料的交叉模型。这种模型简单,易于计算,易于程序化,但弹性常数计算结果有一定误差。本文作者总结了影响三维编织复合材料弹性常数的因素,并首次对三维编织复合材料的交叉模型进行了两次修正。每次修正的原因与结果不同。首先对传统的单向复合材料的体胞模型进行修正;基于此,又考虑了编织体结构的纤维束的曲线弧度的影响,并应用正弦曲线模拟了纤维束的曲线弧度,对模型进行第二次修正。由修正后的交叉模型应用MATLAB计算了三维编织复合材料的弹性模量和拉伸载荷下纤维束截面的应力情况。由两次修正的交叉模型计算的弹性常数与试验结果符合较好。由应力大小分析了三维编织复合材料破坏的应力解释。 

MODIFYING OF GLOBAL-CELL MODEL OF 3-D AND 4-STEP BRAIDED COMPOSITES

A cross model of 3-D braided composites is presented based on elastic theory. The model is simple and programmed easily. Modulus is calculated easily, but certain error exists in results. The author summarizes the factors which affect the elastic modulus of 3-D braided composites and the cross model of the composites is modified twice firstly. The reasons and results of the model modified are different. Firstly, the traditional global-cell model of unilateral composites is modified. Based on this, the model is modified secondly considering the fiber curve radian of fabric structures. And fiber's curve radian is simulated by sinusoid. Using the cross model modified and MATLAB software, the composites modulus and stress on a fiber section at tensile load are calculated. The predicted results of the modulus based on the cross model modified twice are in good agreement with experiments results. The 3-D braided composites mechanism of fracture is interpreted by stress results.