Low velocity impact test is conducted on hybrid fiber honeycomb core sandwich panels filled with different energy absorbing materials such as Rohacell, wheat husk and polyurethane foam (PUF) using an instrumented drop-weight impact testing machine as per ASTM D3763-93 standard. Low velocity impact characteristics such as peak load, absorbed energy and damage mechanisms of the sandwich panels are investigated at 17.16 J, 25.75 J, 34.33 J and 42.91 J energy levels by varying the height of the dropping weight. Image processing technique is performed to calculate the impact damage area of the specimens using MATLAB 2016 A. To observe the damage and failure mode in the failed specimen, optical microscopic observation method is used. As increasing the impact energy, fiber fracture at face sheets, core fractures, delamination between hybrid fabric-epoxy layers and indentations failures are perceived by the visual inspection. According to the obtained results, the low velocity properties such as energy absorption capacity, load at initial damage are significantly improved and impact damage area is decreased considerably by the PUF filled core sandwich panels. Thus, this analysis puts forward that PUF filled honeycomb core sandwich panel may be a preferable material in the field of composites to overcome delamination and impact damages and to reduce the weight especially for the applications of advanced aerospace structures.

低速冲击试验是使用符合ASTM D3763-93标准的仪器化的落锤冲击试验机，对装有不同能量吸收材料（例如Rohacell，小麦皮和聚氨酯泡沫塑料（PUF））的混合纤维蜂窝芯夹芯板进行的。通过改变落锤的高度，研究了低速冲击特性，例如夹层板的峰值载荷，吸收的能量和破坏机理，其能量水平分别为17.16 J，25.75 J，34.33 J和42.91J。使用MATLAB 2016 A进行图像处理技术以计算样品的冲击损伤面积。为了观察失效样品中的损伤和破坏模式，使用了光学显微镜观察方法。随着冲击能量的增加，面板上的纤维断裂，纤芯断裂，目视检查可以看出混合织物-环氧树脂层之间的分层和压痕故障。根据获得的结果，PUF填充芯夹芯板可显着改善低速性能，例如能量吸收能力，初始损伤时的载荷，并显着减小冲击损伤面积。因此，该分析提出，PUF填充的蜂窝芯夹芯板在复合材料领域中可能是优选的材料，以克服分层和冲击损伤并减轻重量，特别是对于先进的航空航天结构的应用。PUF填充芯夹芯板可显着改善初始损坏时的载荷，并显着减小冲击损坏面积。因此，该分析提出，PUF填充的蜂窝芯夹芯板在复合材料领域中可能是优选的材料，以克服分层和冲击损伤并减轻重量，特别是对于先进的航空航天结构的应用。PUF填充芯夹芯板可显着改善初始损坏时的载荷，并显着减小冲击损坏面积。因此，该分析提出，PUF填充的蜂窝芯夹芯板在复合材料领域中可能是优选的材料，以克服分层和冲击损伤并减轻重量，特别是对于先进的航空航天结构的应用。