双轴载荷下缝合层板的强度预测

Strength Prediction of Stitched Laminates under Biaxial Loads

基于缝合层板单层单胞细观力学模型,研究了单层板在拉、压、剪下的力学特性。根据经典层板理论建立了缝合层板在双轴载荷下的强度模型,并考虑了缝合造成表面层和内部层刚度和强度的差异。通过有限元软件ABAQUS分析了双轴载荷多种工况下缝合层板的损伤演化过程,揭示了缝合层板的失效机理,获得了缝合层板在双轴载荷下的失效包络线以及对应比率载荷下的应力应变曲线。所预测的失效模式和失效强度与实验取得了较好的吻合。通过分析表明缝合层板单层在剪切载荷下表现出一定的非线性特性。多轴多向层板在双轴载荷下表现出较强的耦合性。

A representative volume element based on micromechanical model was presented to investigate the tensile,compressive and shear strengths of the stitched lamina.A multi-axial laminate model was built based on the classical laminate theory with the consideration of the difference between external layers and internal layers after stitching.The progressive damage process of the laminates under biaxial loads was analyzed with ABAQUS and the damage mechanisms were proclaimed in detail.The initial and final failure envelopes of the laminate and stress-strain curves under various biaxial loads were obtained.The predicted failure modes and strengths were in accordance with the experimental results,excellently.According to the analysis,single layers of stitched lamina show shear non-linearity under pure shear loads.Multi-axial stitched laminate reveals a strong interrelation between the two directions of loads.