Limiting stress fractures in composite materials
Composite materials are those formed from two or more materials. For example, fibreglass is a composite of glass fibres with plastics and concrete is a composite of gravel and cement. In general, these combinations produce stronger, lighter structures easily compressed without breaking. Composite materials are widely used in the aerospace industry and in civil and mechanical engineering structures that require highly reliable long-term functioning. The 'Reliability of the interfaces on composite materials' (RICM) project was undertaken to extensively characterise the processes and technical parameters involved in fracture initiation at interfaces between materials, propagation of the fracture and eventual failure of structure function. First, the investigators defined new fracture parameters for use in both experimental data collection and development of numerical models. Then, they used a combination of analytical, numerical and experimental tools to better characterise fracture processes. Project partners developed new methodologies to determine stress fields and behaviour of materials. They also defined new parameters for expressing reliability of materials and evaluated damage mechanisms in composite beams. RICM project results provided new insight into fracture processes and characteristics at interfaces in advanced composite materials. This insight should improve reliability and durability of structures produced in the aerospace, civil and mechanical engineering fields, and thus enhance safety.
