【摘要】 对3种截面形状的复合材料长桁实施了2类冲击方向的损伤试验,建立了冲击能量与可见损伤尺度之间的内在联系,并据此确定了3种复合材料长桁产生勉强目视可见冲击损伤(Barely visible impact damage,BVID)所需的临界冲击能量。针对含有BVID的复合材料长桁试样,进行了额外的冲击后压缩试验,测得每种复合材料长桁的剩余压缩强度。研究结果表明,3种不同截面形状的复合材料长桁均呈现一致的规律:相对于面外冲击载荷,面内冲击载荷对应着更小的临界冲击能量以及更大的剩余强度衰减幅度。研究还表明在2种不同方向的冲击载荷影响下,I型长桁具有最高的冲击损伤可见度、且T型长桁居中、J型长桁最弱。同时,T型长桁具有最高的剩余承载能力、且J型长桁居中、I型长桁最弱。综合冲击损伤可见度及剩余承载能力2个关键指标,可认为3种截面形状中,T型复合材料长桁性能最优。更多还原

【Abstract】 Three types of composite stringers were impacted from two different directions. Relationships between impact energy and visible defect length were found. The critical impact energy corresponding to barely visible impact damage(BVID)of each stringer was determined. Specimens with BVID were then compressed to obtain the residual strength. Experimental results showed that for all types of stringers,the critical energy of in-plane impact is always much lower than out-plane ones. In-plane impact causes much more decrement of stringers’ bearing capacity than outplane impact. For both impact directions,I-stringers own the highest defect detectability,T-stringers come second.Meanwhile,T-stringers own the better residual strength ratio than I-stringers and J-stringers. Synthetic considering impact defect detectability and residual bearing capacity after impact,T-stringers own the best compression-afterimpact(CAI)behaviors.更多还原