UBC Theses and Dissertations
Energy absorbing ability of wood/polyester composite laminates Haghdan, Shayesteh
Currently used energy absorbers in transportation industries are made of synthetic fiber/polymer composites as an alternative to their metal counterparts. These composites are stiff and strong but are somewhat brittle when subjected to impact load which limits their application when high energy absorbing ability is required. Wood, in contrast, has a high stiffness and strength to weight ratio and exhibits a higher deflection before failure. Despite the extensive research on the mechanical properties of synthetic fiber/polymer composites few researches are available on the effects of wood composite configuration and densification and its lamination set-up on its impact and compressive properties. This research focused on the use of wood in the form of thin veneer to reinforce polyester and composites of them were fabricated using hand lay-up and compression molding, in different thicknesses. Various wood configurations were used to create unidirectional, cross-ply, and woven mats. The effects of each mat configuration on the impact properties of wood/polyester composites and the lamination and curing processes were investigated and discussed. The gap of knowledge on the wettability of wood to the polyester resin was informed in this dissertation using contact angle measurements and roughness tests. Energy absorbing behavior and dominant fracture mechanisms of wood/polyester laminates subjected to quasi-static compression and shear loading were examined and the results were compared with the lab-made glass fiber/polyester composites. Findings of this study demonstrated that the effect of wood configuration on the impact properties of the polyester composites was significant. Wood densification improved the impact performance of composites but this improvement was not statistically significant. It was found that wood composites had an impact energy equivalent to that of glass fiber laminates.
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Attribution-NonCommercial-NoDerivs 2.5 Canada