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چکیده
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Nowadays, superelastic NiTi stent is used in Thoracic Aortic Aneurysm (TAA) because of its e ective role in minimizing such problems as low twistability, unsuitable dynamic behavior, and shortage of radial mechanical strength. In the simulations, NiTi superelasticity is modeled based on Auricchio's theory and the theory of Tanaka, Liang, and Rogers. Auricchio's model is found to be more consistent with the experimental data than models of Tanaka, Liang, and Rogers. In the present study, a Finite Element Analysis (FEA) was used to evaluate the impacts of applied strain on the superelastic behavior of a novel design for TAA NiTi wire stent, for which axial strain (crushing) and radial strain (crimping) forces were applied. The results showed that NiTi stent with 50% crimping and 90% crushing exhibited the highest mechanical performance owing to suitable Chronic Outward Force (COF), appropriate Radial Resistive Force (RRF), complete mechanical hysteresis pertaining to superelastic performance, and lower stress and greater strain on the internal curvature of the NiTi stent. Finally, this Finite Element Method (FEM) can provide a convenient way for evaluating the biomechanical properties of TAA stents based on the e ect of the strain applied.
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