缝合工艺对复合材料面内弹性模量影响的有限元预报

Finite Element Prediction of the Effects of Stitching on the In-plane Elastic Modulus of Composites

建立了不同缝合密度、不同粗细缝线的碳纤维缎纹增强复合材料三维有限元模型,分别预报了缝线植入处基布全部损伤和部分损伤2种状况的面内弹性模量,并进行了实验验证。结果表明:随着缝合密度增加,复合材料的面内弹性模量降低,最大降低幅度约为44%,泊松比影响很小。较粗的缝线使得复合材料的拉伸剪切弹性模量降低,较细的缝线对面内弹性模量影响较小。与未缝合相比,不同直径的缝线的模量变化在9.6%之内。实验结果与有限元预报的规律一致。

A three-dimensional finite element model of stitched composites reinforced with carbon fiber satin weave fabrics using different stitching densities and stitching threads were established.The in-plane elastic modulus of the composites in two cases that the basic fabrics are completed damaged and partially damaged at the stitches were predicted and verified by experiments.The results showed that the in-plane elastic modulus of the composites decreased up to 44%with the increase of the stitching density,but the effect on Poisson's ratio was insignificant.The thicker stitching thread reduced the tensile shear modulus of the composites,and the thinner stitching threads had less effect on the in-plane elastic modulus.Compared with unstitched composites,the modulus variation of the stitched composites using different diameter stitching threads was below 9.6%.The experimental results were consistent with the finite element prediction.