Z-pin植入密度对复合材料壁板力学性能影响的研究

针对植入Z-pin后的碳纤维增强平纹机织复合材料的微观结构，建立了含Z-pin的机织复合材料单层板和层合板的单胞模型。预报了Z-pin直径、面内分布密对单层板的面内纵向拉伸力学性能的影响，得出了含有Z-pin的机织复合材料单胞在受面内拉伸时，会在Z-pin附近出现应力集中，单胞首先会在应力集中区域发生失效而导致强度降低。通过三维单胞模型模拟了Z-pin在层合板中拉出脱离过程，得出了不同Z-pin直径、不同分离层厚度下的拉拔力—位移曲线。建立了用非线性弹簧模拟Z-pin的双悬臂梁模型，结合VCCT裂纹扩展技术，模拟了含有Z-pin复合材料层合板的Ⅰ型裂纹扩展，得出了Z-pin直径越大，分布越密，层合板的等效Ⅰ型应变能量释放率GIC越大，且直径越大使GIC随裂纹扩展的波动幅度越大，分布越密使GIC波动的波长越小。

Numerical Simulation Research of Inlfuence of Z-pin Implant Density on Mechanical Properties of 2D Woven Composite Laminates

Aiming at the carbon ifber after implantation of Z-pin reinforced plain woven composites microstructure, the cell model woven composite materials containing Z-pin and laminates was established. The prediction effect of density of monolayer plate surface in the longitudinal tensile properties of Z-pin diameter, surface distribution, the Z-pin containing single cell in woven composites under in-plane tension, will appear in the vicinity of the Z-pin stress concentration, the cell will be the ifrst in the area of stress concentration caused failure strength decreased. Through the three-dimensional model of the single cell model, Z-pin was pulled out of the process, and the drawing force displacement curves of different Z-pin diameter and different separation layer thickness were obtained. A double cantilever beam model to simulate the Z-pin with nonlinear springs, combined with the expansion technology of VCCT to simulate the crack, crack containing Z-pin composite laminates obtained Z-pin expansion, the larger the diameter, the more dense distribution type, the equivalent strain energy release rate of composite laminates GIC greater volatility and the diameter of the ambassador GIC with the crack distribution is bigger. The distribution of crack is more dense, the GIC wavelength is smaller.