Z-pin增强树脂基复合材料单搭接接头抗冲击性能

为了研究Z-pin增强树脂基复合材料接头的抗冲击性能，制备了Z-pin增强单搭接接头冲击试样。对比不同树脂体系Z-pin/层合板界面裂纹扩展，分别通过Z-pin拔脱试验和接头剪切试验研究Z-pin冲击后拔脱强度和单搭接接头冲击后剪切强度；结合有限元模拟和超声C扫描研究搭接面分层损伤情况。结果表明，相同冲击能量下，环氧Z-pin/环氧层合板界面抗冲击性更强，冲击能量越大，裂纹扩展越显著；Z-pin增强树脂基复合材料显著减小分层损伤面积，提高冲击后剪切强度，体积分数为1.5%、直径为0.5mm的Z-pin增强层合板分层损伤面积仅为40%，冲击后剪切强度的下降率仅为24.89%。随着Z-pin体积分数增加，搭接面损伤面积逐渐减小，冲击后剪切强度先增加后降低；随着Z-pin直径增加，层间损伤面积增加，冲击后剪切强度逐渐降低。Z-pin增强接头分层损伤模型模拟结果与试验结果基本吻合。 

Impact resistance performances of resin matrix composite single lap joints reinforced by Z-pin

To study the impact resistance performances of resin matrix composite joints reinforced by Z-pin, single lap joint specimens reinforced by Z-pin were prepared. The crack propagation along Z-pin/laminates interface was compared with different resins matrix of Z-pin. Z-pin pullout and lap shear tests were carried out to study the after-impact pullout strength of Z-pin and after-impact shear strength of single lap joint, respectively. The ultrasonic C-scan method combined with finite element simulation was utilized to explore the delamination damage area of joint interface. The results showed that compared with the BMI resin matrix Z-pin, the resistance performance between epoxy Z-pin/epoxy laminates was stronger at the same impact energy. With the increase of impact energy, the crack propagation was more significant. Z-pin reinforced resin matrix composites remarkably reduced delamination damage area and improved the after-inpact shear strength. The delamination damage area of joint reinforced by Z-pin was 40%, and its reduction of after-impact shear strength was 24.89% when Z-pins volume fraction was 1.5% and diameter was 0.5mm.With the increase of Z-pin volume fraction, the delamination damage area decreased gradually, while the after-impact shear strength increased firstly and then decreased. The damage area of lap surface increased as the increment of Z-pin diameter while the after-impact shear strength decreased. The results of finite element modeling were consistent with the test results.