含分层损伤缝合复合材料层板的剩余压缩强度

Prediction of Residual Compressive Strength of Stitched Composite Laminates with a Delamination

基于渐进损伤方法,研究了含单脱层缝合复合材料层板在压缩载荷下的剩余强度。通过商用软件ABAQUS建立了含单脱层缝合复合材料层板剩余压缩强度计算模型,考虑了子层屈曲和分层扩展对剩余强度的影响。通过UMAT子程序实现了层板失效、层间失效和缝线失效的模拟。通过嵌入式杆单元结构模拟了缝线桥联作用及失效。采用Hashin准则及刚度折减法对纤维拉压、基体拉压失效进行了模拟。通过渐进损伤分析,揭示了缝合情况下含单脱层复合材料层板的失效机理,讨论了缝合参数对剩余压缩强度的影响。所预测的破坏模式和剩余强度结果与实验能较好地吻合。分析表明缝合可以明显提高含分层损伤复合材料层板的子层屈曲载荷,抑制分层扩展,并提高层板的剩余压缩强度。

Based on a progressive damage method, the mechanical behaviors of stitched composite laminates containing initial delamination were investigated. A finite element （FE） model was established to predict the residual compressive strength through ABAQUS. Laminate buckling and delamination propagation were considered during the analytical process. The failures of laminates , interlaminar and stitching were simulated by UMAT subroutine embedded truss elements were used to provide the bridge-forces of stitching. Hashin criterion and stiffness reduction method were introduced to predict fiber failure and matrix failure. The progressive damage process was investigated and the damage mechanisms were analyzed in detail. Effects of different stitching parameters on residual compressive strength were discussed. The predicted failure modes and strength have excellent agreement with experimental results. It shows that stitching increases laminate buckling load-capacity, restrains delamination propagation and increases the residual compressive strength.