Z-pins几何分布对其增强复合材料双悬臂梁Ⅰ型层间韧性的影响

Effect of Z-pins distribution on mode Ⅰ delamination toughness of Z-pinned laminated double cantilever beam specimens

复合材料Z-pinning增强技术通过在层合板内嵌入体分比小于5%的Z-pins,能大幅度提高层合板的层间断裂韧性,减少因低能量冲击所产生的分层损伤。本文作者基于细观力学模型,构造了相应的Z-pin单元;结合梁单元,建立了用于分析含Z-pins的双悬臂梁(Double cantilever beam,DCB)的有限元模型;在分层裂纹面上引入接触单元以防止分析过程中2个分层子梁在分层前缘处的相互嵌入。通过数值算例分析了Z-pins对层间韧性增强效果的影响及其原因。数值计算结果表明,Z-pins的几何分布对其增强层间韧性的影响相对较小。

With less than 5 % volume fraction of through-thickness Z-pins insertion, the delamination toughness of Z-pinned laminates can be improved significantly and the delamination area induced by low-energy impact can also be reduced greatly. Based on the currently available Z-pin micro-model, a Z-pin element was developed and a beam element model for Z-pinned double cantilever beam （DCB） specimens was proposed in this paper to study the effect of Z-pins distribution on the mode I delamination toughness of Z-pinned DCB specimens. A contact element is also in- troduced to the proposed model to avoid the unrealistic penetration of the two substrate beams at the delamination crack tip. The numerical results show that the Z- pin distribution has an insignificant effect on the mode I delamination toughness of the Z-pinned laminated DCB specimens.