Analytical Modeling of Piezo-SMA Composite as an Actuator and Energy Harvester

Piezoelectric materials and shape memory alloys (SMAs) are very common materials for actuators and sensors; however their composites as electrical generators are least explored, although the use of piezoelectric materials as the mechanical energy harvester is becoming popular. In this dissertation piezoelectric material and SMA are used as constituents for an active composite of two types; one is a composite of piezoelectric material and SMA as an actuator and the second one is a composite as a thermal energy harvester. The analytical modeling and experimental study related to Piezo-SMA active composites are examined for both cases. Eshelby's inclusion problems are combined into a single model to treat the coupled behavior of electro-mechanics inherent in the piezo-SMA composite where the piezo is matrix phase and SMA is filler phase. SMA undergoes phase transformation such as stress-induced martensite transformation and temperature induced austenite transformation. Basic design and experimental work done on active composite are discussed in the areas of material characterization and mechanical modeling.