The Interfacial Fracture Of Bonded Materials And Composites

Adhesive bonding and composite materials have been widely used in manufacturing industry. Failure results from the weakest link in a structure and this is often the interface between two materials. In case of composites, it becomes the fiber and matrix interface. In case of bonded polymers, the bonding line is the interface. This Dissertation is focused on the interfacial fracture of bonded materials and composites. First, a systematic experimental investigation on adhesive bonding strengths of polymer/polymer and polymer/metal joints was conducted and the experimental results were compared with other researchers\u27 work. Then, a modified short-beam shear approach is developed to measure the Mode II fracture toughness of unidirectional composites. Two advantages of this approach which are pure shear stress state at the bonding interface and prevention of early failure of unidirectional composites was proved by finite element analysis. Finally, the failure predication and stress field calculation of sharp notch bonded with two materials is discussed. Finite element method with cohesive element is adopted to predicate the fracture initiation load. Both finite element and asymptotic method is used to analyze the stress field