SMA’s have a wide range of applications in engineering and medicine because of their special properties. For example, they have been used in aerospace, structure engineering, bio- mechanics and robotics. Because of the complex structure of shape memory alloys, applicable equations for common metals can not predict the behavior of these alloys. SMA torque tubes produced from these alloys have been recently used in several areas due to their special properties. One of their properties which have a major application in aerospace and machinery is recovering torque produced with restricting the thin walled shape memory torque tube and then raising temperature. This property enables producer to use these SMA tubes instead of motors for producing torsion torque. Because of the many difficulties for modeling of shape memory alloys, a three dimensional model based on “Micro Plane” theory has been used to simulate the behaviors. Simulations in this thesis include simulation of tension- torsion behavior of shape memory torque tube at a constant temperature, simulation of the recovery shear stress along limiting SMA Torque Tube and changing temperature, a constrained tube with varying temperature, and simulation of cyclic behavior at tension-torsion as well as study of Non-proportional tension-torsion loading at two states. The results show a good agreement with those obtained by other researchers. To compare these results with experimental ones, a tension-torsion device has been manufactured for tension-torsion loading in this thesis. At first, this device is tried for thin walled steel tube but, because of existence of sleep in device’s clamp, an error is shown leading to the need of more experiments. Key Words Shape Memory Alloys, SMA Torque Tube, Microplane Theory, Simulation, Experimental Results
