Theoretical and experimental study on the influence of fiber orientation on the tensile properties of unidirectional carbon fiber/epoxy composite

Probably-one of the most popular advantages of fiber-reinforced polymer composites is the capability to tailor their mechanical properties and, therefore, their behavior to an externally applied load. Regarding the layup manufacturing process, fiber orientation plays a fundamental role in the tensile resistance of carbon fiber-reinforced epoxy CFRE composites. Therefore, this work is aimed to realize a better understanding of the influence of fiber orientation on the tensile properties of CFRE composites. The study is conducted mathematically and experimentally on test samples with 0°, 30°, 45°, 60°, and 90° fiber orientations. The maximum tensile stress values obtained from tensile tests are compared to the calculated ones through four basic failure models; maximum stress, maximum strain, Tsai–Hill, and Tsai–Wu. The results of the investigation indicate that the error between theoretical and measured values are highly affected by the fiber orientation of the composite. The experiments demonstrate that the resistance of CFRE composite to the tensile loading is mainly dependent on the fiber orientation. In particular, test specimens with 0° fiber orientation show maximum failure resistance (σ = 2857 MPa) compared to other orientations. Additionally, the orientation of fiber is found to have a substantial influence on the composites’ Young’s modulus. Maximum tensile strain at Yield (7.1 %) is obtained at 45° fiber orientation. The findings are anticipated to be guidelines for the design optimization of CFRE composite subjected to pure tension force.