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Poly epoxy is a high performance room temperature cured epoxy system which provides excellent physical and mechanical properties. However, the effects of post curing of this resin system on the properties of different sandwich structures are unknown. This study aims to evaluate the effect of post curing (at 70°C for 2 hr) on the edgewise compressive and flexural strengths of a sandwich structure, constructed with Styrofoam and honeycomb as core materials and a plain weave carbon fabric as face sheet. Tested factors evaluated from edgewise compressive tests were as follows: peak load, compressive strength, and crash energy absorption of sandwich structures while core shear stress and bending stress of sandwich structures were determined and compared with flexural tests. It was observed that post curing affects significantly on the bending and compressive strengths of the sandwich structures. However, the data obtained for crash energy absorption suggested that the effect of post curing on the core shear strength and the total deflection was statistically insignificant. The matrix polymer was also inspected using dynamic‐mechanical thermal analysis to assess the changes in glass transition temperature and degree of conversion due to post cure. POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers

The advanced composite materials are increasingly being used in the automotives for their ultralight physical properties and super strong mechanical properties. This research examines the cost‐effective single‐step liquid resin infusion manufacturing process for developing all composite car body as the generally used sheet molding compound manufacturing process is highly capital intensive. Three different scaled down models of the Eco car were developed focusing on minimal weight and air drag coupled with aesthetics. Structural design and analysis was carried out using the Pro/E and Ansys tools. The Pro‐E model was scaled up to generate computer‐aided drafting drawings for tool development. Different stations were marked on the model and sliced virtually for development of pattern. Moreover, the mold was manufactured from carbon and glass/polyester composites for prototype manufacturing of the car body. This involved manual placement of desired number of carbon layers as preform on female side of the mold. The vacuum sucked the resin through a number of carefully selected entry ports which ensured effective resin distribution and impregnation. Polycarbonate wind shield was thermoformed in the convection oven according to streamlined geometry of car body and hinged. The car body was integrated with the compatible floor panels and accessories. The crumble zone shock absorber in the bumper was manufactured using successive layers of nomax honeycomb and polyvinyl chloride rigid foam to dampen the accidental shock. The car performed remarkably well in the Eco marathon race held at Malaysia, 35:97–104, 2014. POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers