Several definitions for shape memory alloys have been proposed, but as the simplest definition one can say these alloys are a group of materials in which permanent strain could be completely recovered due to heating. Of course this is just one of the significant characteristics of these alloys called “Shape memory effect”. Another characteristic of these alloys is “Psuduelastic” in which strain due to loading at high temperatures completely recovers during unloading. Nowadays these alloys have variable uses in different industries such as medical, aerospace and robotics technology. In this thesis, thermomechanical behavior of these alloys in psuduelastic mode is studied. Since these alloys have vast usage in the form of wire for example as actuators; simulation of their behavior under tensile test is studied in this thesis. Providing usual “dogbone” sample for tensile test out of these alloys is somehow impossible because it makes the simulation far from reality. Moreover, since these alloys are very sensitive to stress concentration so the required machining for producing this shape, adversely affects the behavior of these alloys. On the other hand there is no modified standard for tensile test with circular samples even for ordinary materials. So at first, using a finite element simulation, maximum applicable force on wire before the occurrence of slip is proposed. Then it was proved that results could be use for different material behaviors. Stress concentration caused by grippers over wire could dramatically affect the behavior of these materials. So a simple study took place on the span of this stress concentration based on which a minimum length is proposed for tensile test of these materials. For modeling the behavior of these materials under tensile test, at first the effect of martial parameters on the stress distribution along the length of wire is studied. Then, using a finite element simulation on tensile test of an elastic wire, the stress distribution along the length is obtained and used for simulation of a shape memory alloy. Using this stress distribution and a temperature distribution proposed by a thermomechanical model, tensile test is modeled. Finally for more accurate simulation, a simple method for predicting stress distribution along the length of wire is proposed and used for modeling the behavior of these materials to simulate the tensile test more exactly. With this method, finite element simulation of fastening the grippers when the wire is still elastic is utilized. After this step, stress and radius distributions are calculated by the proposed model. Using this stress distribution along with temperature distribution, again behavior of these materials under tensile test is simulated. In order to evaluate the model, some tensile tests were performed and then the experimental conditions were exactly used for simulations. The predicted nominal stress-strain and local-nominal strain curves by the simulations are compared to the experimental results. The very good agreement between the results showed the ability of the proposed model in predicting the effect of changes in material parameters and conditions of surrounding media. Keywords: Thermomechanical model, Shape memory alloys, Finite element, local-global strain