Investigation On Low-velocity Impact Of Composite Panels Reinforced By Woven Spacer Fabric

The problem of low-velocity impact on composites have always been a hot issue in the field of materials. Low-velocity impact will cause some invisible damage that will seriously affect the mechanical properties of the composites. Predecessors have done a lot of research for the composite panels reinforced by woven spacer fabric that is manufactured with glass fiber as the raw material, on low-velocity impact problem. This paper discussed the low-velocity impact problem and the lateral pressure strength after low-velocity impact. Finally, the process of low-velocity impact was simulated by the finite element simulation. The research content mainly includes several aspects:Firstly, high-strength low-stretch polyester industrial filament which was instead of usual glass fiber was used to manufacture woven spacer fabric as fiber materials. This paper designed five species of woven spacer fabric in different fineness of binder yarn. Then, polyurethane foam which was chosen as the fill material and epoxy resin which was chosen as the matrix resin were used to manufacture the composite panels reinforced by woven spacer fabric.Then, the experiment of low-velocity impact was beginning. The paper investigated if changing the fineness of the binder yarn and position of low-velocity can affect the property of against low-velocity impact. The conclusion indicated that the damage would increase by increasing the fineness of the binder yarn. Moreover, comparing the impact on the position of the binder yarn with not on, it was found that when the impact happened on the position of the binder yarn the visible impacting damage was more obvious then that of the other positions.Next, the remaining lateral pressure strength was studied. The conclusion indicated that the low-velocity impact can reduce the lateral pressure strength and change the damage mode. On the other hand, at the same impact energy acting, the binder yan was more thicker and the decay rate of composite panel was lower. That means it can remain more the lateral pressure strength. Moreover, changing the position of low-velocity impact made different the lateral pressure strength. After impacting occurred on the position of the non-binder yarn, delamination was occurred on the composite panels. After impacting occurred on the position of the binder yarn, bending was occurred on the composite panels. When the impact energy was large enough, the difference was not obvious.Finally, the process of the low-velocity impact was simulated by Explicit Dynamics in ANSYS. It was found that the simulation coincided the trend of low-velocity impact. But it was not accurate, it need to be optimized further.