CAJ | 학술논문

复合材料各向异性和吸能的特点，在受到外来冲击作用时容易产生损伤，呈现表里迥然不同的损伤行为和分布规律。为研究不同复合材料层压结构的冲击损伤行为，设计制备树脂传递模型工艺(Resin transfer molding, RTM)缝合和预浸料复合材料层压结构两种不同成型工艺的试样，通过冲击试验模拟复合材料在外力作用下产生的冲击损伤，采用超声反射法，通过点聚焦换能器对试样进行超声 B 扫描成像，揭示两种复合材料层压结构试样内部断面损伤行为及其扩展规律。试验结果表明，冲击引起的试样内部损伤比表面损伤要大得多；随着冲击能量在试样内部传递，会在不同深度铺层产生新的损伤，而且损伤分布并不仅沿层间界面扩展；冲击点附近和远离冲击点附近的内部损伤具有明显不同的分布规律；RT M 缝编与预浸料复合材料结构呈现明显不同的损伤行为，其中RT M缝合复合材料结构中的纵向缝线，对冲击损伤在试样内部沿层间的扩展有显然的阻止作用。研究结果对更好地理解复合材料的损伤行为、寻找新的改进复合材料层压结构损伤行为的机制有非常重要的指导意义和帮助。
복합재료각향이성화흡능적특점，재수도외래충격작용시용역산생손상，정현표리형연불동적손상행위화분포규률。위연구불동복합재료층압결구적충격손상행위，설계제비수지전체모형공예(Resin transfer molding, RTM)봉합화예침료복합재료층압결구량충불동성형공예적시양，통과충격시험모의복합재료재외력작용하산생적충격손상，채용초성반사법，통과점취초환능기대시양진행초성 B 소묘성상，게시량충복합재료층압결구시양내부단면손상행위급기확전규률。시험결과표명，충격인기적시양내부손상비표면손상요대득다；수착충격능량재시양내부전체，회재불동심도포층산생신적손상，이차손상분포병불부연층간계면확전；충격점부근화원리충격점부근적내부손상구유명현불동적분포규률；RT M 봉편여예침료복합재료결구정현명현불동적손상행위，기중RT M봉합복합재료결구중적종향봉선，대충격손상재시양내부연층간적확전유현연적조지작용。연구결과대경호지리해복합재료적손상행위、심조신적개진복합재료층압결구손상행위적궤제유비상중요적지도의의화방조。
Composite laminates are very sensitive to foreign impact because of their anisotropy and good absorbing ability to impact energy. They may exhibit different impact damage behavior in body under impact loading. Two kinds of specimens-RTM-stitched and prepreg composite laminate, are manufactured to investigate their behaviors of impact damages. The specimens are subjected to a given energy impact. An ultrasonic B-scan is arranged to the specimens by using focal system in order to study behaviors of impact damages in cross-sections of the specimen bodies. Experimental results have demonstrated that interior damaged area is much larger than damage on surface;new damages occur in different inetrlaminar layers with impact energy going into specimen body deeper and deeper, and they evolve not only along interfaces of layers;the distribution and orientation of damages between near-and far-impact point are significantly different; a clear difference in damage behavior between RTM-stitched and prepreg composite laminates is demonstrated very well, and the stitching fiber thread in depth direction of RTM-stitched composite laminate has obvious help on restriction to development of damages along interlaminar interfaces. The results provide very helpful and practical understanding of the damage behavior in different composite laminate bodies. That may motivate to find new mechanism to improve damage behavior of composite laminates.