Aspects concerning the degradation of the elastical and mechanical characteristics at bending of the composite materials made of E glass fibres reinforced polymeric resins because of the moisture absorbtion

Abstract

Abstract: The paper describes the aspects concerning moisture absorption on the behaviour at bending in case of composite materials made of E-glass fibres reinforced polymeric resins. These fibres were used to randomly reinforce the following resins: two polyester resins (Heliopol 8431 ATX, Polylite 440-M880), epoxy resin LY 554) and vinyl-ester resin (Atlac 582). The first of all, experimental data concerning moisture absorption was analysed during ten months. Three different environments were considered: water, water / detergent mix and natural seawater (Black Sea). Then, the composite material specimens were subjected to the flexural test (three point's method). The results obtained in case of the submerged specimens (9200 hours) were compared with the results obtained in case of the dry specimens. Finally, the conclusion was that the moisture absorption in composite materials tested leads to the decreasing of the flexural mechanical characteristics (elastic flexural stress sigma(e),flexural modulus E and failure energy). The paper briefly describes the laboratory tests and shows graphically the final results.