含孔型缺口的纤维金属层板剩余强度

纤维金属层板(fiber metal laminates,FMLs)作为混合层板家族中一员,由铝合金层和预浸料层交替铺设而成.相比于铝合金板,含缺口的纤维金属层板强度下降更为明显.为研究含孔型缺口的纤维金属层板的剩余强度,测试了光滑试样的静力拉伸性能和缺口试样的剩余强度.分析了铺层结构对剩余强度的影响,引入应力失效模型预测了纤维金属层板含孔型缺口的剩余强度,讨论了含缺口纤维金属层板的失效模式、损伤萌生和扩展过程.结果显示:带孔GLARE3层板的强度下降约为40%,铺层增加后缺口敏感性下降,特征长度增加,约在90%的剩余强度时缺口处有损伤发生.

Residual Strength of Notched Fiber Metal Laminates

Fiber metal laminates (FMLs) are a family of hybrid materials consisting of alternating thin coatings of aluminum alloy and fiber-reinforced epoxy layers. In contrast to aluminum alloys， the presence of notches in FMLs causes significant strength reduction. To evaluate the residual strength of fiber metal laminates with circular open hole， mechanical testing was performed to determine the un-notched tensile properties and notched strength of FMLs. The influence of ply structure on residual strength of FMLs was investigated. The stress failure model was introduced to predict the residual strength of FMLs with an open hole. Failure modes， damage initiation and progression of notched FMLs were also characterized and discussed. The results show that the presence of a hole in GLARE3 laminates gives a strength reduction about 40%. It can be seen that the characteristic length increase and notch sensitivity tends to decrease with the increase of ply number. The damage initiated at the hole edge when the residual strength is 90%.