材料期刊网

层间短纤维强韧化是复合材料层合板层问增韧的有效途径之一. 采用三维非线性有限元方法分析了层间短纤维强韧化复合材料层合板的分层扩展问题, 探讨其影响因素. 以混合模式下通用裂纹扩展的能量准则作为分层扩展判据, 通过虚拟裂纹闭合技术计算分层尖端能量释放率. 用节点双编号和单元生死技术模拟分层扩展. 采用弹簧单元模拟层间短纤维作用, 通过改变弹簧刚度修正短纤维桥联力. 采用GAP元处理分层区的接触非线性问题. 分析了分层区桥联力对层间应力场、位移场以及分层扩展的影响. 研究结果表明, 层间短纤维有效延缓了分层扩展, 增韧效果明显.

Toughening from interlaminar short fibers is one of the effective ways of interlaminar toughening in composite laminates. In order to study the effects of interlaminar short fibers on the delamination growth in composite laminates, the delamination growth in composite laminates with interlaminar short fibers was studied by 3D geometrically nonlinear and contact FEM. The FEM was improved with the virtual crack closure technique to calculate the energy release rate, and the current fracture criterion in mixed mode was used as the criterion for crack propagation. The crack propagation was simulated by node coupling/partition and the technology of element living and death. The effect of interlaminar short fibers was simulated by spring elements, and the bridging force of short fibers was modified by changing the spring stiffness. The GAP element method was used to deal with contact problems. The influence of interlaminar bridging stress on delamination front stresses, displacement and its growth was studied. Compared with delamination growth in composite panels without interlaminar short fibers, the results show that interlaminar short fibers can effectively reduce the delamination growth and enhance the interlaminar toughness.