Mechanical and tribological behavior of fiber-reinforced polymer composites with varying fiber orientations and ANN-based COF prediction

In this study, mechanical and tribological properties of carbon fiber/epoxy (CF/epoxy), glass fiber/epoxy (GF/epoxy) and hybrid carbon-glass fiber/epoxy (CGF/epoxy) composites with two laminate orientations (90/45/90/135/90) and (0/135/0/45/0) are investigated. Different loads (20–50 N) and frequencies (5–11 Hz) were used in tensile, flexural, interlaminar shear, density, microhardness and reciprocating sliding tests. The (90/45/90/135/90) architecture showed the best tensile properties with tensile strength of 637.55 MPa and Young’s modulus of 23.21 GPa for CF/epoxy, while the (0/135/0/45/0) architecture showed the best flexural properties with flexural strength of about 950 MPa for GF/epoxy. The COF and wear of CF/epoxy were lowest, and the wear of GF/epoxy was highest, compared to CF/epoxy, GF/epoxy showed 34.3% higher wear loss, and 16.2% higher specific wear rate for the (90/45/90/135/90) architecture. The (0/135/0/45/0) architecture resulted in the lowest wear loss and specific wear rate for all the composite systems, and CF/epoxy exhibited the best wear resistance. The measured void contents of CF, GF, and CGF composites were 13.27%, 15.47%, and 14.34%, respectively. Damage to the matrix, fiber fragmentation, and wear debris were observed on the worn surfaces using SEM analysis. An ANN model was used to predict COF with R ² values of 0.91759 and 0.87056 for validation and testing respectively. In general, the results show that the type of reinforcement and laminate architecture have a significant influence on the mechanical, frictional and wear properties of the composite materials studied.