Effect of different temperatures and water aging on the mechanical properties of aramid/carbon reinforced elium matrix composites

In this thesis, the mechanical performance of intraply aramid/carbon hybrid fiber reinforced thermoplastic Elium matrix composites was experimentally investigated under the effects of different temperatures and water aging. Mechanical properties were determined by tensile, flexural, SENB and DCB tests. Tests were carried out at -50, -25, 0, +25 and +50 °C to evaluate the effects of different temperatures. The tensile strength of the specimens at +25 °C was 513.19 MPa and increased by 4.93% at -50 °C compared to +25 °C, while it decreased by 9.00% at +50 °C. The flexural strength was 291.55 MPa at +25°C, 389.90 MPa at -50°C and 234.66 MPa at +50°C. In SENB tests, the fracture toughness at +25°C was 138.83 MPa√m, while 151.04 MPa√m and 126.27 MPa√m were determined as a result of tests at -50 and +50°C, respectively. In DCB tests, the Mod-I fracture toughness obtained at +25°C was 1123.39 J/m2, while it was 1240.30 J/m2 and 1242.61 J/m2 at -50 and +50°C, respectively. In the context of water aging, tests were conducted on unaged specimens as well as those aged in distilled water for 2, 4, and 6 months. Compared to unaged specimens, tensile strength decreased by 4.40%, flexural strength decreased by 25.89% and fracture toughness decreased by 21.56% in SENB test after 6 months of aging. In DCB tests, the Mod-I fracture toughness obtained in unaged specimens increased by 32.14% after 6 months of aging.