缝合泡沫夹层复合材料低速冲击数值模拟及实验

在ABAQUS分析平台中建立了缝合泡沫夹层复合材料在低速冲击下的动力学有限元模型,采用杆单元模拟缝线树脂柱的作用,基于Hashin破坏准则模拟层板面内损伤,通过各向同性硬化本构模型利用等效塑性变形模拟泡沫夹芯损伤演化。针对相同铺层的缝合和未缝合泡沫夹层结构,模拟了相同冲击能量下的低速冲击响应过程及面板、泡沫的损伤情况,数值结果与实验结果吻合较好,证明了该方法的有效性和准确性。研究结果表明,在低速冲击下,泡沫夹层结构引入缝线后虽然降低了泡沫缓冲吸能的作用,使得面板表面受到较大的冲击破坏,但增强了整体刚度,增大了面板抵抗弯曲变形的能力,减小了内部面板的损伤,使其在改善复合材料面板易分层缺陷的同时还依然拥有优良的面内性能。

Numerical Simulation and Experiment of Low-Velocity Impact on Stitched Foam Core Sandwich Composites

A dynamics finite element model was established for the stitched foam core sandwich composite laminate under low velocity impact in ABAQUS.The stitching resin columns were described as truss elements in the model.Hashin failure was used to predict the intralaminar damage of laminate,and crushable foam model with isotropic hardening was used to predict the evolution of foam damage.The low-velocity impact response and damage of stitched/unstitched foam core sandwich structure were simulated by this method.The numerical results well agree with the experimental results and it verified the effectiveness and accuracy of the model.The results show that under the low-velocity impact the foam core sandwich structure added suture line can reduce the foam cushioning effect to get larger impact damage on the surface of laminate but it can increase the ability of laminates deformation resistance to get smaller damage of the inner laminate.It can not only improve the defect of laminate easy-layered but also still has excellent intralaminar property.