Impact study of particle strengthened fibre reinforced polymer composites
Poo, Benjamin Wei Jun
Date of Issue2017-05-23
School of Mechanical and Aerospace Engineering
Composite materials are becoming increasingly used due to their high strength and stiffness to weight ratio over conventional materials like metals. This facilitates the creation of highly efficient structures which weigh less while retaining the same strength. New materials are constantly being created each day to further strengthen composites and it is of interest to find the best combination of materials available. In this project, composites are manufactured with thin and thick bi-angle carbon fibre plies with novel liquid thermoplastic PMMA resin and thermoset epoxy resin. Furthermore, these composites were toughened with the addition of C/SH particles in the interfaces. Baseline comparisons without C/SH particles were also manufactured. The C/SH particles were activated using the ex-situ method which involves the activations of particles before the RTM injection process. The optimization of the ex-situ method was achieved successfully in this project to suit the RTM manufacturing process. In-plane and out of plane tests were carried out on the composite specimens to characterize the impact properties as well as investigate the changes in flexural and damping properties. C/SH particles were seen to increase the load bearing capacity by 7% when 3.75% C/SH weight percentage was introduced into thick PMMA composites, toughening in interply regions was also observed in all specimens. The PMMA resin was seen to exhibit high strain rate characteristics as there was increase in peak load when indentation speed was increased from 1mm/min to 5mm/min and 10mm/min. The usage of thin bi-angle plies iv improved peak load performance by up to 5% as compared to thick bi-angle plies despite the same total ply weight and C/SH weight percentage per interface (% of ply weight). The same toughening effect was present with thin epoxy composites when C/SH particle were introduced. Tan δ increased by up to 19% with thick PMMA composites with 3.75% C/SH weight percentage, 7% with thin PMMA composites when compared to thick PMMA composite counterpart and 9% with thin epoxy composites when 0.875% C/SH weight percentage was added. Flexure test also showed no significant changes in flexural strength and modulus with the addition of C/SH particles.
Final Year Project (FYP)
Nanyang Technological University