缝纫泡沫夹芯复合材料的刚度预测与试验验证

基于材料细观结构,建立了缝纫泡沫夹芯复合材料的刚度预测模型,并进行了刚度性能的相关试验验证。其中,对缝纫复合材料层合面板部分,考虑了缝纫角对单胞尺寸和富脂区大小的影响,以及缝纫前后层合面板厚度的变化对复合材料面板纤维体积含量的影响,采用改进的纤维弯曲模型计算了缝纫复合材料层合面板的刚度;对缝纫增强的泡沫夹芯部分,把缝线树脂柱看作是泡沫基体中的增强相,将其简化为特殊的单向增强复合材料,提出了用串并联组合模型来预测其刚度。试验测试了缝纫泡沫夹芯复合材料板试件的刚度。应用本文模型对缝纫层合面板和缝纫泡沫夹芯复合材料板的刚度进行预测,结果均与试验结果吻合较好。采用理论模型系统研究了缝纫参数和结构参数对缝纫泡沫夹芯复合材料刚度的影响。

Theoretical prediction and experimental study of the stiffness of stitched foam-core sandwich composites

 A stiffness prediction model was established for stitched foam-core sandwich composites based on the microstructure, and the equivalent stiffness was also achieved by experiments. Considering different sizes of representative volume element (RVE) and resin enriched zone caused by different stitching angles, a modified fiber waviness model was developed to evaluate the stiffness of stitching laminated face-panels, and the effect of thickness variation of the face panels after stitching was also included. The stitched foam core, stiffened by the resin cylinder, was simplified as a unidirectional composite, and its stiffness was estimated by a mixed series parallel model. Stiffness experiments of stitched foam-core sandwich composite panels were performed. The predicted equivalent moduli of the stitched face panel and the stitched foam-core sandwich panels show good agreement with the experimental data. The effects of stitching parameters and structural parameters on the stiffness were discussed.