缝合复合材料泡沫夹芯结构剪切刚度预报

Shear Stiffness Prediction of Stitched Composite Sandwich Structure with Foam Core

针对复合材料泡沫夹芯结构的缝合工艺采用代表体元法,通过建立有限元模型,对这种新型复合材料结构的剪切刚度性能进行了预测。考察了缝合对材料弹性常数的影响,给出了弹性常数的计算方法,并着重探讨了纤维弯曲、富树脂区以及缝线刚度、缝线等效直径对结构剪切刚度的影响。对比发现:结构的面内剪切刚度与缝线直径成反比,与缝线的剪切刚度成正比;面外剪切刚度与缝线直径成正比,与缝线的剪切刚度成正比。数值分析结果与试验结果比较吻合。

To quantify the effect of through-thickness stitch on shear mechanical properties, a three-dimensional finite element unit-cell model was developed. The representative volume element method and suitable boundary condition were adapted to the model. Disturbed fiber orientation within laminate ply, rich-resin zone caused by stitching and the properties and equivalent diameter of stitch lines were taken into account. A comparison among the calculated results, indicates that the structural stiffness in-plane decreases when diameter of stitches increases, and increases when stiffness of stitches increases; the structural stiffness out-plane increases as the diameter or the stiffness of the stitches increases. The results from numerical analysis coincide with the experimental data well.