Determination of fracture toughness of particulate reinforced composites

Composite materials are produced by combining two or more materials at macro level in order to create new material with superior properties which have better properties than its constituent materials. Composite materials are used as the alternative materials to the conventional materials in many engineering applications due to their superior properties such as lightness, high impact strength, high corrosion resistance, and appropirate thermal properties. Fiber reinforced composite materials are the most used composite material type in the structures. Glass, carbon, aramid, and boron fibers are the major reinforcement materials which are used in the fiber reinforced composite materials. But, either the manufacturing cost of such unnatural fiber is expensive or waste emission into the environment during their manufacturing encourage researchers to find more eco-friendly solutions. Due to low energy cost for manufacturing of natural fibers without carbon emissioning into the environment during their manufacturing, this type of fibers are prefered. Since the natural fibers have low strength value when compared with the petroleum-based fibers, to enhance mechanical strength of composite materials, they are reinforced with different materials in certain rates. The most prominent method is to make particle reinforcement into composite materials. In this project, fracture toughness of jute/epoxy laminated composites, which were reinforced with ceramic particles, were determined under Mode I, Mode I-II, and Mode II loading condition. In this extend, jute/epoxy composite plates with six lamina, which were reinforced with silicone carbide (SiC) having 4,5µ, 9,3µ, and 53µ particle size and 0%, 3%, 6%, and 9% reinforcement ratio, were manufactured. Compact tension shear (CTS) test specimens were cut according to the ASTM standard from manufactured composite plates. CTS test specimens were exposed to tensile test at different angle (0º, 30º, 45º, 60º, and 90º) by using Arcan test fixtures. After fracture tests the surface morphology of damaged specimens were photographed with scanned electron microscope (SEM) to better understand the effect of particle size and reinforcement ratio of SiC on the fracture toughness. Another study in the project were determined of the fracture toughness of jute/epoxy composite plate, which have ceramic particle reinforcement by using Ansys finite element package program with J-integral method. For this, mechanical properties of jute/epoxy laminated composites, which have reinforced with different particle size and ratio, were determined, experimentally.