Corrugated structures reinforced by shape memory alloy sheets: Analytical modeling and finite element modeling

2018 ◽  
Vol 233 (7) ◽  
pp. 2445-2454 ◽  
Author(s):  
Maryam Koudzari ◽  
Mohammad-Reza Zakerzadeh ◽  
Mostafa Baghani
Keyword(s):  
Finite Element ◽  
Shape Memory Alloy ◽  
Shape Memory Alloys ◽  
Finite Element Modeling ◽  
Shape Memory ◽  
Smart Structure ◽  
Design Parameters ◽  
Asymmetric Mode ◽  
Element Modeling ◽  
Structure Changes

In this study, an analytical solution is presented for a trapezoidal corrugated beam, which is reinforced by shape memory alloy sheets on both sides. Formulas are presented for shape memory alloys in states of compression and tension. According to the modified Brinson model, shape memory alloys have different thermomechanical behavior in compression and tension, and also these alloys would behave differently in different temperatures. The developed formulation is based on Euler–Bernoulli theory. Deflection of the smart structure and the effect of asymmetric response in shape memory alloys are studied. Results found from the semi-analytic modeling are compared to and validated through a finite element modeling, and there is more than [Formula: see text] agreement between two solutions. With regard to the results, the neutral axis of the smart structure changes in each section. The maximum deflection ratio of asymmetric mode to symmetric one mode is 1.7. Additionally, the effect of design parameters on deflection is studied in detail.

Finite element simulation and optimization of radial resistive force for shape memory alloy vertebral body stent

2017 ◽  
Vol 28 (15) ◽  
pp. 2140-2150 ◽  
Author(s):  
Rong Wang ◽  
Hong Zuo ◽  
Yi-Min Yang ◽  
Bo Yang ◽  
Qun Li
Keyword(s):  
Finite Element ◽  
Response Surface Methodology ◽  
Shape Memory Alloy ◽  
Finite Element Modeling ◽  
Shape Memory ◽  
Response Surface ◽  
Vertebral Body ◽  
Resistive Force ◽  
Topological Structures ◽  
Element Modeling

Vertebral body stent of shape memory alloy is an innovative device which helps recover the compression fractural vertebral at normal height due to its excellent superelasticity and the shape memory effect. A finite element modeling is carried out to optimize the mechanical behavior of the vertebral body stent of shape memory alloy accounting for the stress-induced phase transformation of the shape memory alloy. The radial resistive force of stent is paid more attention in order to meet the functional and surgical requirement. First, experimental procedure and finite element modeling computations are constructed to calculate the compression resistance force of an original design of vertebral body stent of shape memory alloy. It is found that numerical results are consistent with those of experimental observations so as to validate the accuracy of the finite element modeling model. Second, a series of numerical simulations are performed to optimize the topological structures of vertebral body stent of shape memory alloy by response surface methodology. The surgical condition of the lumen structure of fracture vertebral body and the size constrain condition of puncture instrument of minimally invasive surgery are introduced during finite element modeling simulation and response surface methodology optimization. Finally, an innovative design optimization is proposed by the series–parallel connection of four S-type representative stents. The proposed new structure can obtain the maximum radial resistive force of 831 N which is able to meet the functional requirement. In conclusion, it is expected that the finite element modeling simulations and optimizations can help the researchers to design and optimize the topological structures of vertebral body stent of shape memory alloy systems.

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