T700/QY8911缝合复合材料细观力学模型研究

Study on Micro-mechanical Model of the T700/QY8911 Stitched Composite

建立了两种缝合复合材料单层细观力学几何模型。通过考虑缝线引起面内纤维弯曲角度的梯度渐变分布和纤维弯曲区域宽度的范围,以T700/QY8911缝合复合材料为例,用细观力学方法和数值积分方法分别计算了两种模型的弹性常数和拉伸强度。计算及试验结果表明,缝合引起的面内纤维弯曲变形导致了复合材料纵向弹性常数下降;无论增强纤维最大弯曲变形程度为何值,当纤维弯曲区域宽度越小,纤维弯曲区域宽度对纵向弹性模量的影响越大;即缝线引起纤维在针脚附近只有部分纤维发生弯曲变形比纤维全部发生弯曲变形得到的结果更准确。

Two micromechanics models of stitched lamina composites are established. Considering induced fiber bend angle gradient distribution and fiber bending region width by the suture, with T700/QY8911 stitched composite as an example, the elastic constants and the tensile strength of two kinds of models are calculated by using micromechanics method and numerical integral method. Calculation and experimental results show that the longitudinal elastic constant of the composite material is decreased due to the suture causing the fiber bending deformation. Whatever the maximum bending deformation value of the reinforcing fiber is, the smaller the width of the curved re- gion of fiber is, the larger influence it will have on. It is concluded that the analysis of part fiber bending deforma- tion causing by stitching is more correct than the whole area.