A systems approach to modelling and design of high strain shape memory alloy actuators /

A simulator is developed to model and design high strain shape memory alloy (SMA) tension actuators. The simulator may be used to predict characteristics of a given actuator, or to design its geometry under specifications such as force, speed, stroke and size. The accuracy of the model is verified experimentally in reference to an existing NiTi shape memory alloy prototype actuator. Having developed some confidence in the model, the performance of the proposed actuation mechanism is compared to other existing technologies. In particular, the force-displacement and speed characteristics of a micro-solenoid electro-magnetic actuator and a muscle-size pneumatic actuator are compared to those of the SMA actuators with same dimensions.A new concept of designing shape memory alloy bending actuator is presented in the end of the thesis. Part of the modelling work is accomplished in this research by developing a software simulator which is capable of predicting the geometric transformation of the actuator during bending. As a result, the dynamic strain of each SMA fiber in the actuator can be computed given a bending axis and angle. Graphical display of the bending transformation is implemented using in house software package. Further investigation of modelling and control of the SMA bending actuator is left as future work