考虑就位效应的大开口层合板拉伸失效预测

Failure prediction of tensile strength of laminated composites with big cutouts considering in-situ effect

为更精确预测大开口复合材料层合板的失效模式和破坏强度,考虑子层就位效应建立大开口层合板渐进损伤分析模型。使用ABAQUS软件进行大开口层合板拉伸模拟,通过编写USDFLD子程序,分别设置失效准则以及刚度退化模型。设置失效准则时考虑层合板各子层的就位横向拉伸强度和面内剪切强度。结果表明:开口越大,层合板的破坏载荷值越低,[±45]5铺层相比[0/90]5铺层的大开口层合板承载能力弱;[0/90]5铺层的大开口层合板主要从应力集中处沿垂直于拉伸方向的截面断裂破坏,[±45]5铺层的大开口层合板从应力集中处沿纤维与基体的界面开裂破坏;层合板子层就位特性的破坏载荷预测值比未考虑就位效应的预测值更接近试验值,渐进损伤分析得到的破坏模式与试验结果吻合良好,验证了渐进损伤分析模型的正确性。

In order to more accurately predict the failure mode and the tensile strength of composite laminates with big cutouts,a progressive failure model of composite laminates with big cutouts considering in-situ effect was created.Tensile simulation of big cutouts composite laminates was performed by using ABAQUS.USDFLD was applied as a subroutine to set failure criterion and stiffness degradation separately.The in-situ transverse tensile strength and in-situ shear strength of laminates were considered while setting the failure criterion.The results show that the bigger of the cutout size,the lower of ultimate load.The[±45]5 crossply laminate with big cutouts has lower ultimate load than[0/90]5 cross-ply laminate.The failure of[0/90]5 cross-ply laminate develops mainly from the stress concentration area along the direction perpendicular to the tension direction,and[±45]5 crossply laminate expands along the interface of fiber and matrix.The predicted values considering the in-site effect fit better with the test data than those without considering the in-situ effect.The progressive failure mode fits reasonably well with the test results,which verifies the established progressive failure model.