Smart composite panels with embedded peak strain sensors

Composite laminates are finding increasing use in load bearing structures of a safety critical nature. This trend means that it becomes increasingly important to be able to measure the accumulated damage within safety critical composite panels. The current research approaches include the use of piezoelectric patches, fibre optics, and even the intrinsic piezoresistive properties of carbon fibres themselves. The aforementioned methods do, however, suffer various difficulties in terms of manufacturing considerations, as well as the complexities associated with some of the monitoring equipment needed to interpret damage levels. A more robust concept has however recently seen development, which relies on embedding metastable ferrous elements or wires within the laminate. Not only can this smart material easily withstand the processing temperatures; but if correctly used, the elements may impart significant load-bearing capacity to the laminate. The damage assessment equipment is simple and can in fact be operated by a person with no specialised training.