缝合复合材料层板低速冲击损伤研究

通过三维动力学有限元法，以空间杆单元模拟缝线的增强作用，建立了缝合复合材料层板在横向低速冲击载荷作用下的渐近损伤分析模型。该模型考虑了缝合层板受低速冲击时的纤维断裂、基体开裂及分层等五种典型损伤形式，采用基于应变描述的Hashin失效准则和Yeh分层失效准则，并将其嵌入ABAQUS/Explicit用户子程序以实现相应损伤类型的判断及其材料性能退化。针对相同铺层的缝合与未缝合层板，模拟了低速冲击作用下的冲击响应和渐进损伤过程，数值结果与试验吻合较好，证明了该方法的合理有效性。同时探讨了冲击速度、缝合密度等对缝合层板冲击响应和损伤的影响。结果表明：有、无缝合层板的低速冲击响应具有类似的变化规律，缝合能够有效减小冲击损伤面积。随着缝合密度和缝线强度的增大，缝合对冲击损伤的抑制作用更为明显。

STUDIES ON LOW-VELOCITY IMPACT DAMAGE OF STITCHED COMPOSITE LAMINATES

A 3D dynamic finite element model with stitching threads which are described as the spatial truss elements is proposed to predict the progressive damage of stitched laminates.Combined with the user-defined material constitutive program of ABAQUS/Explicit,the typical failure modes,such as fiber break,matrix crushing,matrix cracking and delamination are simulated by employing the strain-based Hashin and Yeh failure criterion The dynamic response and damage propagation of stitched/unstitched laminates were sim...