抄録
The durability, especially the fracture and fatigue characteristics, of smart materials including Ni-Ti-based shape memory alloys (SMAs) and piezoelectric ceramics, is presented. It is shown that these materials may suffer degradation in toughness, which must be duly considered in their intended applications. Composite structures with embedded superelastic SMA wires can be properly designed and fabricated in order to enhance their impact damage resistance against delamination and fibre breakage. Smart composite patches using SMA wires may also be used to repair cracked structures and hence control crack growth. Theoretical modelling and calculations for the design of such patches are given. Similarly, applications and analyses of piezoceramic wafers for shape and vibration control of structures, and piezo-electric active fibres for the arrest of crack growth in composites laminates using controllable closure stresses are illustrated. Finally, an artificial damage detection system and methodology for delamination and hole-type damages in composites structures is discussed and examples are given to demonstrate its applicability and usefulness.
