Experimental Studies of Leak Pressure of Frp Butt Joint between Two Aluminum Pipes

A FRP butt-joint was formed between two adherends of aluminium pipe of outside diameter of 25.40 mm and inside diameter of 22.20 mm. The joint was formed by winding a wetted roving of glass fiber / carbon fiber with controlled quantity of epoxy at ±45° angle. It was cured to form the joint with a glass fiber reinforced polymer (GFRP) / carbon fiber reinforced polymer (CFRP) sleeve around the joint plane. For checking leakages in this joint dead weight pressure gauge tester was used. It can be inferred that pressure at which leakage takes place through FRP joint is directly proportional to the number of passes of glass / carbon fiber roving. It is because when number of passes of glass fiber increases, more compact FRP joint is formed which can undertake more pressure. Specimen with lesser number of passes of glass fiber / carbon fiber, leak through center of FRP joint while specimen of higher number of passes leak through either upper or lower side of FRP joint. During leak test, when the pressure inside the aluminium pipe increases, hoop stress also increase leading to expansion of aluminium pipe thereby forming the strong matrix of FRP. This formation of strong matrix increases the pressure at which leak occurs i.e. it enhances the results.