The dynamic response of composite sandwich beams to transverse impact
The dynamic response of composite sandwich beams to transverse impact
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DOI：
10.1016/j.ijsolstr.2006.07.015
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发表时间：
2007-04
影响因子：
3.6
通讯作者：
V. Tagarielli;V. Deshpande;N. Fleck
中科院分区：
文献类型：
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作者：
V. Tagarielli;V. Deshpande;N. Fleck
玻璃纤维-乙烯基酯复合梁的动态响应是通过用金属泡沫射弹撞击跨中梁来测量的。梁以复合材料整体形式存在，并采用夹层结构，具有复合面板和由 PVC 泡沫或端纹轻木制成的芯材。高速摄影用于测量梁的瞬态横向偏转并记录变形和破坏的动态模式。对于整体式和夹层式配置，弯曲波从冲击部位向支撑件传播。整体梁和夹层梁的最终失效是由于面的拉伸撕裂造成的。夹层梁还表现出芯材开裂和面板分层。梁的动态强度通过梁跨中的最大瞬态横向偏转作为弹丸动量的函数来量化。事实证明，夹层梁的性能优于同等质量的整体梁。芯强度和芯厚度之间的权衡使得低密度PVC泡沫芯优于较高密度PVC泡沫芯。端纹轻木在压缩和剪切方面比 PVC 泡沫具有优异的刚度和强度。因此，对于低动量射弹，具有轻木芯的夹层梁优于具有 PVC 泡沫芯的梁。在弹丸动量较高的情况下，顺序会发生逆转：具有轻木芯的夹层梁会因沿纹理分裂而在纵向剪切中过早失效。
The dynamic response of glass fibre–vinylester composite beams is measured by impacting the beams at mid-span with metal foam projectiles. The beams exist in composite monolithic form, and in sandwich configuration with composite face-sheets and a core made from PVC foam or end-grain balsa wood. High-speed photography is used to measure the transient transverse deflection of the beams and to record the dynamic modes of deformation and failure. For both monolithic and sandwich configurations, a flexural wave travels from the impact site towards the supports. Ultimate failure of the monolithic and sandwich beams is by tensile tearing of the faces. The sandwich beams also exhibit cracking of the core, and face-sheet delamination. The dynamic strength of the beams is quantified by the maximum transient transverse deflection at mid-span of the beams as a function of projectile momentum. It is demonstrated that sandwich beams can outperform monolithic beams of equal mass. The trade-off between core strength and core thickness is such that a low density PVC foam core outperforms a higher density PVC foam core. End-grain balsa wood has a superior stiffness and strength to that of PVC foam in compression and in shear. Consequently, sandwich beams with a balsa core outperform beams with a PVC foam core for projectiles of low momentum. The order reverses at high values of projectile momentum: the sandwich beams with a balsa wood core fail prematurely in longitudinal shear by splitting along the grain.