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Go to Editorial ManagerThe mechanical behavior of multilayer FRCMs was tested, and the effects of fibers, types of fiber, and laminates on the tensile, flexural, and impact properties were discussed. The vacuum bagging method is a composite manufacturing process that uses atmospheric pressure to consolidate laminate layers, remove excess resin, and get rid of air bubbles. This makes high-quality, void-free composites. Four composite systems were made using this method: natural fiber composites reinforced with sheep wool and goat hair fibers, and synthetic fiber composites reinforced with carbon and glass fibers, all with an epoxy resin (LR620) and hardener (LH620) system. All composite assemblies have been systematically characterized at different layer configurations (3-6 layers considered) for the best structural response. The tensile, flexural, and impact properties were tested by following the corresponding ASTM (D638, D790, D6110) standards, respectively. The tensile and flexural results of the carbon fiber composite (GCT, GCB series) showed excellent mechanical performance (maximum tensile strength of 283 MPa for GCT4 and flexural strength of 164 MPa for GCB5) with high load-carrying capacity, but the failure was brittle. Goat hair composites exhibited excellent impact resistance (GHI4: 1.255 J) and moderate tensile strength (36 MPa), which indicated superior energy absorption capacity. The glass fiber composites showed a good balance of mechanical properties with increased ductility, where the tensile strength was 245 MPa, and a large deflection capacity was reached (14.683 mm). The study demonstrates that 4-layer setups usually result in the highest tensile properties, while 5–6-layer setups improve the flexural strength. These results add to the knowledge of optimization of multilayer composite design, and they are very useful for materials selection in aerospace, automotive, and structural applications.
In this study, the mechanical properties of an epoxy, unidirectional woven carbon and fiberglass composite were investigated experimentally. ASTM used for preparing the composite specimen. Different ranges of mixing ratios of woven carbon and fiberglass with epoxy are studied. Tensile, impact and bending test are carried out to investigate the mechanical properties for produced new composites. After testing the mechanical properties of the specimens, it is noted that adding of unidirectional woven carbon layers will leads to strengthens the samples. The mechanical properties of woven carbon composite are far superior to those of woven carbon composite with fiberglass.
The field of mechanics concerned with studying the propagation of cracks in materials is Fracture Mechanics. Technology systems are meant to withstand the loads to which they are likely to be exposed when in use. Material imperfections arising at the time of production or use of the material are, however, unavoidable and must therefore be taken into account. A stress intensity factor is a fracture parameter that defines the part failure. This paper study’s the effect of cracks on the stresses of rectangular plates having a hole in the center. The plate was subjected to tensile pressure at the top side while maintaining the bottom side fixed. The plate had four cracks distributed around the centered hole at 45o at each side. The effect of the length of the cracks on the resulted stresses and strains was investigated. Also, the effect of the position of the crack on the resulted stresses and strains was studied. Finite element models for the different plate cases were built using ANSYS software. The results showed that increasing the crack length resulted to increase the stresses and strains. The dimension of the plate width, height and thickness were 150 mm, 300 mm and 1 mm respectively, and the crack position was investigated for different crack lengths (5, 10, 15, 20, 25 mm) however the results were not steady as it looks that the crack lengths have changed the stress distribution over the plate.