孔口缝合补强对含孔复合材料层板应力集中影响的数值模拟

提出的一种缝合线计算模型,通过数值模拟计算与实验结果比较,得到缝合线计算模型中相关的弹性参数.对复合材料开口缝合补强结构进行有限元模拟计算,分析了孔边及邻近区域应变、应力的分布规律,得到不同缝合参数、孔边不同位置以及不同载荷条件下的应变、应力集中系数,并给出合理的孔口缝合参数设计方法及相关结论.研究结果表明:含孔拉伸试件在孔边θ=0°处,切向拉伸应力最大;在θ=90°处,切向压缩应力最大;在孔口0°和90°之间存在拉应力与压应力的转换点,缝合补强后,此转换点大约在θ=56°左右.

Simulating Calculation of the Effect of Stitching Reinforcement on Composite Laminates with a Circular Hole

A calculation model of stitching thread was presented. Based on the numerical simulation and the experiment results, the elastic properties parameter of stitching thread were obtained. The finite element simulating calculation was carried out on the effect of stitching reinforcement for composite laminates containing a circular hole. The strain and stress distribution regularity were investigated analytically. The hole edge coefficients of strain and stress concentration were calculated for different stitching parameters, external load, the edge location of the hole. There exists a transform point from tensile stress to compressing stress between 0° and 90° point around the hole, i.e.σ_θ=0 at the transform point. The transform point is about θ=56° reinforced by stitching. A stitching design parameters on the edge of hole are made and give some useful conclusions.