Reduction in process-induced shape distortion of C-shaped composite parts using micro silica particles

During the fabrication of composite parts, the residual stresses build up causing the shape distortion in laminated composites and deteriorate its mechanical performance. In the case of angled/cylindrical parts, the stress leads to the change in the encircled angle. The effect of adding nano/microparticles on the mechanical properties has been the focus of many researchers in the recent past, but their effect on the process induced shape distortion of composite parts has been studied rarely. This study investigates the effect of silica particles on shape distortion in glass/unsaturated polyester cross-ply C-shaped composite parts having an enclosed angle of 240°. Composite parts were fabricated with a varying fraction of silica particles (0, 3, 5, and 7% by weight of resin). In order to analyze curing behavior, thermal kinetics of the resin system was investigated using differential scanning calorimetry (DSC). The experimental results showed that the value of diameter reduction was reduced from 6 mm to 3 mm by addition of 5% silica particles. Furthermore, composite part distortion was predicted using an analytical model and compared with experimental results for validation.