《Ductile–brittle fatigue and fracture behaviour of aluminium-PMMA bimaterial 3PB specimens》.pdf

Available online at Engineering Fracture Mechanics 75 (2008) 674–681 /locate/engfracmech Ductile–brittle fatigue and fracture behaviour of aluminium/PMMA bimaterial 3PB specimens G. Shatil a,*, A. Saimoto b, X.J. Ren c a MBN Technology Ltd., Bristol BS3 2AR, UK b Graduate School of Science and Technology, Nagasaki University, Nagasaki 8528521, Japan c School of Engineering, Liverpool John Moores University, Liverpool L3 3AF, UK Received 11 December 2006; received in revised form 17 March 2007; accepted 17 March 2007 Available online 31 March 2007 Abstract Fracture toughness and fatigue crack growth tests and numerical simulations on 3PB specimens were carried out to study the behaviour of a crack lying perpendicular to the interface in a ductile/brittle bimaterial. Polymethylmethacrylate acrylic (PMMA) and aluminium alloy 2024 T531 were joined together using epoxy resin. A precrack was introduced into the ductile material and tests were carried out to obtain fracture toughness and fatigue properties. The body force method and elastic–plastic finite-element analyses were used to simulate the experimental stress intensity KI and cracking behaviour under monotonic and cyclic loads. It was found that the bimaterial fatigue crack growth rate is higher than that for mono- lithic aluminium 2024 but lower than the rate for a monolithic PMMA. This agreed with the trend for the fracture tough- ness values and was consistent with the numerical method results. The initial Mode I stable ductile cracking in