ガラス繊維強化プラスチック(GFRP)の応力腐食に及ぼすマトリックス樹脂の影響

The stress corrosion properties of GFRP, made of glass cloth or glass chopped strand mat and unsaturated polyester resins, have been evaluated under acidic conditions. Four types of unsaturated polyester resins were used as the matrix. Each matrix resin has a different fracture toughness level.The retention strength of the cloth-GFRP and mat-GFRP under acidic conditions were 20-40% and 40-80% of the original strength in air, respectively, at a very slow tensile rate. The retention strength vs. fracture toughness curve showed the existence of an optimum value in matrix toughness for the high performance of stress corrosion.The fatigue induced cracks did not give any degradation in the tensile strength in air, but decreased the tensile strength of GFRP significantly under acidic conditions. The results show that the fracture toughness of matrix resin is a critical parameter in determining the rate of fatigue crack propagation.