低速冲击对K-cor夹层结构力学性能的影响

K-cor夹层结构是应用Z-pin技术增强的一种新型高性能夹层结构，本文基于落锤冲击实验对低速冲击下K-cor夹层结构的力学性能进行了研究，结合红外无损检测和冲击后压缩强度（CAI）试验，对不同Z-pin植入参数和芯材厚度对K-cor试样的冲击损伤阻抗进行了深入研究。研究结果表明：K-cor夹层结构的芯材越厚，则其冲击损伤面积越大，但剩余压缩强度比越高；在不超过植入间距的前提下，增加Z-pin的折弯长度能显著的降低K-cor结构冲击后的损伤面积，提高压缩强度；在相同芯材密度的情况下，提高Z-pin的折弯长度比增大植入密度更有利于减少K-cor试样冲击后的损伤面积，提高试样的压缩强度和其剩余压缩强度比。

Effect of low-velocity impact on mechanical properties of K-cor sandwich structure

K-cor sandwich structure is a new type of high-performance foam structure reinforced by Z-pinning techniques. By using drop hammer test, as well as infrared non-destructive testing and compression-after-impact (CAI) strength test, this paper studies the shock resistance of K-cor structure with changing parameters of Z-pin and core thickness under low velocity impact. Experimental results indicate that the thicker the core is, the larger the impact damage area is, and the higher the compression strength retention is. When the increase of the bending length of Z-pin is not more than the implanted spacing, the impacted damage area of K-cor structure can be significantly reduced, and the compression-after-impact strength can be enhanced. When the density of the core is the same, improving the bending length of Z-pin, rather than the implanted density, can reduce the damage area and increase the ratio of compression-after-impact strength to strength retention of the sample.