Impacts, which may occur during manufacture, service or maintenance, are the major cause of in-service damage to composite structures. Many investigations have been undertaken in order to assess and locate impact damage. A new method of impact location in composite materials is proposed in this paper. It based on a classical sensor triangulation methodology and combines experimental strain wave velocity analysis with an optimization genetic algorithm procedure. The method is validated on a composite panel with embedded piezoceramic sensors. The paper shows that the new method has potential for effective impact damage location. Strain data from only three piezoceramic sensors provide good impact location results, avoiding learning and modelling difficulties associated with other techniques.

Impacts can inflict serious damage on composite structures. For structures on the surface of an aircraft this has potentially critical consequences. The problem is exacerbated by the fact that the damage is internal, with little or no indication on the surface of the structure, making it difficult to detect. A potential solution to the problem would be an impact monitoring system that could detect when an impact occurred. This idea was explored using a composite panel, inside which a SMART Layer was embedded. Two techniques were studied that were able to estimate the locations of impacts on the panel from the measurements provided by the piezoelectric strain sensors in the SMART Layer. The first technique employed artificial neural networks and the second used a triangulation procedure incorporating a genetic algorithm. The knowledge acquired during the study made it possible to develop a simple and efficient prototype impact monitoring system for the composite panel.