含分层损伤复合材料层板压缩分层疲劳扩展研究

Progressive Delamination Growth in Composites Laminates Under Compressive Fatigue Load

采用基于Mindlin一阶剪切理论的连续壳单元,建立了预测含分层损伤复合材料层板在压缩疲劳载荷作用下的分层扩展3D模型,分析了含穿透分层复合材料层板在压缩疲劳载荷作用下的分层扩展行为。利用累积损伤理论,对层板内出现的各种典型损伤进行相应的刚度折减,并在循环加载过程中对材料性能进行强度弱化。利用虚裂纹闭合技术(VCCT)计算分层前缘处的能量释放率,结合混合断裂判据判断分层是否扩展,进而得到压缩疲劳载荷作用下分层扩展规律。计算模型通过大型商用有限元软件和自编程序实现。通过对数值仿真结果和试验结果进行比较,验证了模型的合理性和准确性。

Based on the Mindlin first order shear deformation theory, a 3D finite element model for simulating progressive delaminaton growth in composite laminates with delamination damage under fatigue load is performed. Based on damage cumulating theory, the strain-based failure criterion with corresponding stiffness degradation technology is adopted to the model during fa- tigue damage. The VCCT technology is used for modeling the region between two laminas. The initial and evolution of interlaminar damage is decided by mixed mode energy released rate failure criterion. And the interracial damage near the interface crack tip and the development ofdelamination in the component are obtained. The total model is implemented by commercial finite element software with its user subroutine. A good agreement is obtained between numerical analysis and experimental results.