Comparison of the post-impact behavior of tubular braided and filament wound glass/polyester composites under compression

Abstract

In this study, different tubular braided and filament wound structures were produced using a Maypole braiding machine with glass fiber and then consolidated with unsaturated polyester resin using the Vacuum Infusion Process (VIP). For experimental tests, half of the samples were impacted in the center with 2. 74 J impact energy. Then the compression test was conducted on all of the specimens. Graphs of force-elongation were obtained and the failure works of the specimens were calculated. It was observed that non-impacted filament wound tubular composites have 34% higher failure work than those of their braided counterparts with the same fiber volume fraction (FVF), which is due to the existence of more reinforcing layers in filament wound structure compared with braided composites. The braided composites with the same number of layers as filament-wound ones have higher FVF and higher wall thickness, hence, show higher compression properties. However, the drop of compression properties after the impact load is significantly higher in filament wound composites compared with the braided ones with the same FVF. Therefore it can be concluded that the interlacing structure of fibers in braided composites controls the delamination and restricts the propagation of cracks in the structures after being subjected to impact loads, and causes a less drop in the compression properties of the composites.