Z-pin增强复合材料帽型加筋壁板接头拉伸性能

为了提高复合材料帽型加筋壁板结构中筋条与蒙皮界面处的连接强度,引入Z-pin三维增强技术。制备了Z-pin增强帽型接头试样,并对其进行拉伸试验,研究Z-pin对帽型接头界面增强机理及不同Z-pin体积分数、直径及加载跨距对筋条与蒙皮界面处连接性能的影响规律。结果表明:Z-pin直径为0.5 mm、植入角度为90°时,在体积分数0%~1.0%范围内,Z-pin增强帽型接头拉伸强度随着体积分数的增加而增加,增长趋势随体积分数增加而减缓,含1.0% Z-pin增强帽型接头比未增强接头强度提高了31.2%,在体积分数1.0%~1.5%范围内,Z-pin增强帽型接头拉伸强度呈降低趋势;Z-pin直径对帽型接头拉伸强度影响不显著;随着加载跨距的增加,含0.5%(直径0.5 mm)Z-pin增强帽型接头伴随有失效模式转变,拉伸强度呈现降低趋势。

Tensile performance of composites' hat stiffener reinforced wall joint by Z-pin

To enhance the joint strength on interface between the skin and the stiffener of polymer composites' hat stiffener wall structure, the 3D reinforcing technology of Z-pin is used for hat stiffener wall joints. Hat joint specimens reinforced with different configurations of Z-pin are manufactured and tested by tensile, the mechanism reinforced with Z-pin is analyzed and the effects of the volume fraction, diameter of the Z-pin and load span on the joint performance on interface between the skin and the stiffener are investigated. It turns out:when Z-pin's diameter is 0.5 mm and implant angle is 90°, the joint strength increases with Z-pin volume fraction increasing from 0% to 1.0%, but its increase trend slows down with Z-pin volume fraction increasing, the strength of hat joint with Z-pin fraction of 1.0% is higher than that without Z-pinned by 31.1%, thus the Z-pinned hat joints pull-off strength decreases with Z-pin volume fraction from 1.0% to 1.5%. The effect of the diameter of Z-pin on the pull-off strength of hat joint is not significant. With the increasing of the load span, the pull-off strength of hat joints reinforced with Z-pin fraction of 0.5% (diameter of 0.5 mm) decreases with the failure model transforming.