多轴向织物层合板层间剪切强度有限元分析与实验研究

用VIMP工艺制备了UD、0/45/-45、0/45/90/-45三种多轴向织物增强,四种厚度的GFRP层合板试样,采用短梁剪切实验考察了层间剪切强度和破坏模式。建立了GFRP层合板短梁剪切试样有限元模型,计算了内部层间剪应力分布。结合计算和实验结果分析表明层合板存在由宽度方向层间剪应力变化导致的自由边缘效应,含偏轴铺层的层合板更容易发生边缘开裂破坏。厚度相同时0/45/-45多轴向织物增强层合板的层间剪切强度最高。短梁剪切强度测试存在尺寸效应,随着厚度的增加,强度下降,样品波动系数增大。

FEM Analysis and Experimental Investigation on the Interlaminer Shear Strength of the Multi-axial fabric Reinforced Laminate

3 kinds of laminate samples reinforced by UD, 0/45/-45, 0/45/90/-45 multi-axial fabric respectively, were manufactured by the vacuum infusion moulding process. Each laminate had 4 types of thickness. Experiment was made to investigate the short-beam shear strength and the failure mode of them. The finite element model of the short-beam shear sample was established, and the interlaminar shear stresses in different positions were calculated. The result shows that the free edge delamination failure is liable to occur with the increment of the off-axis plies which is mainly due to the stress gradient through the width direction. The interlaminar shear strength of the 0/45/-45 laminate is the highest of the 3 kinds of laminate with the same thickness. There are size effects in the short-beam shear strength test, the shear strength decreases while the sample coefficient of variation increases with the thickening of laminate.