三维角联锁机织复合材料剪切性能有限元分析

使用三维绘图软件Pro/E 5.0构建出一种三层角联锁机织复合材料的细观结构模型,借助有限元软件ANSYS对复合材料在剪切力作用下纤维与树脂的应力、应变分布进行数值模拟,并借此分析该复合材料在剪切作用下的力学行为,并预测复合材料破坏模式。结果表明:复合材料在剪切力作用下发生沿剪切力方向程度较均匀的剪切变形;纤维相对于树脂承受更多剪切力作用,产生更大应力,但发生相对较小的应变;纤维中轴向与剪切力方向平行的经纱相对轴向垂直于剪切力的纬纱表现出更大的应力和应变。     

Experimental and numerical investigation of mechanical behavior of plain woven CFRP composites subjected to three-point bending

The mechanical behavior of plain woven Carbon Fiber-Reinforced Polymer (CFRP) composites under Three-Point Bending (TPB) is investigated via experimental and numerical approaches. Multiscale models, including microscale, mesoscale and macroscale models, have been developed to characterize the TPB strength and damages. Thereinto, Representative Volume Elements (RVEs) of the microscale and mesoscale structures are established to determine the effective properties of carbon-fiber yarn and CFRP composites, respectively. Aimed at accurately and efficiently predicting the TPB behavior, an Equivalent Cross-Ply Laminate (ECPL) cell is proposed to simplify the inherent woven architecture, and the effective properties of the subcell are computed using a local homogenization approach. The macroscale model of the TPB specimen is constructed by a topology structure of ECPL cells to predict the mechanical behavior. The TPB experiments have been performed to validate the multiscale models. Both the experimental and numerical results reveal that delamination mainly appears in the top and bottom interfaces of the CFRP laminates. And matrix cracking and delamination are identified as the significant damage modes during the TPB process. Finally, the quasi-static and dynamic behaviors of plain woven composites are discussed by comparing the results of Low-Velocity Impact (LVI) and TPB simulations.     

拉伸载荷下正交三向机织复合材料接头失效多尺度渐进损伤分析

针对机械打孔三维机织复合材料耳片接头的单轴拉伸破坏性能，采用多尺度分析方法研究孔边纱线破坏过程。结果表明，正交三向（ORT）机织复合材料接头孔边的连续的经纱出现大量的纵向损伤；纬纱单元出现大量横向损伤，损伤沿着孔边45°方向逐渐扩展，纬纱发生剪切失效，最终接头的损伤形式为剪切破坏。数值模拟和试验结果的误差为1.14％，验证了多尺度有限元仿真方法的正确性。孔边细观区域的纱线损伤从孔边扩展到边接头边缘。孔边纱线的分布位置不同，纱线的破坏形式虽不一样，但是不影响破坏的扩展趋势。