Interfacial aspects of fiber reinforced brittle/ductile dual matrix composites using micromechanics techniques and acoustic emission

Interfacial bonding and microfailure modes of glass fiber reinforced brittle unsaturated polyester/modified epoxy composites were investigated via micromechanics techniques and acoustic emission (AE). Various silane coupling agents were used to observe the comparative interfacial bonding. In the brittle matrix layer, the more the numbers of cracking increased, the higher the interfacial bonding was improved under both dry and wet conditions. This might be due to the chemical and hydrogen bondings in two interphases. A reasonable correlation among microdroplet, fragmentation tests and model system was found. This can be performed by associating AE parameters. AE data showed the sequential occurrence of main three groups of AE. The first group was originated mainly from brittle matrix cracking. The second and the third resulted from the fiber breakages and complex ductile matrix cracking including debonding, respectively. The micromechanical tests for dual matrix specimens provided more reliable information on the interfacial adhesion and charaterized microfailure modes when combining AE technique.