Superelastic shape memory alloy flag-shaped hysteresis model with sliding response from residual deformation: Experimental and numerical study

2019 ◽  
Vol 30 (12) ◽  
pp. 1823-1849 ◽  
Author(s):  
ABMR Haque ◽  
Anas Issa ◽  
M Shahria Alam
2019 ◽  
Vol 30 (15) ◽  
pp. 2283-2298
Author(s):  
Zhixiang Rao ◽  
Xiaojun Yan ◽  
Xiaoyong Zhang ◽  
Bin Zhang ◽  
Jun Jiang ◽  
...  

Currently, most wire-woven trusses are fabricated with traditional metals such as steel and aluminum, thus the deformation ability is constrained due to the low yield strain of common metals. Shape-memory alloy is a kind of smart material which can bear large recoverable strain while producing hysteresis. Due to the unique capacity of large deformation and remarkable damping property of the shape-memory alloy, a novel lattice trusses assembled by superelastic shape-memory alloy coil springs was proposed. Furthermore, the treatment processes to prepare the shape-memory alloy coil springs and the assembly method to fabricate the shape-memory alloy wire–woven trusses were also introduced. The quasi-static compression under different maximum deformation and temperatures was performed to investigate the mechanical and thermal responses of the proposed shape-memory alloy wire–woven trusses. Cyclic compression tests were also performed to study the functional fatigue of the shape-memory alloy wire–woven trusses. The proposed wire-woven trusses can undergo up to 80% deformation by compression and recover without evident residual deformation after unloading. Finite element analysis simulation of representative volume element under different deformation was presented. Analytical modeling of the stiffness of shape-memory alloy wire–woven trusses was also carried out. Both the numerical and analytical methods can predict the stiffness within a small deviation.


2019 ◽  
Vol 14 (01) ◽  
pp. 2050001
Author(s):  
Jize Mao ◽  
Daoguang Jia ◽  
Zailin Yang ◽  
Nailiang Xiang

Lack of corrosion resistance and post-earthquake resilience will inevitably result in a considerable loss of function for concrete bridge piers with conventional steel reinforcement. As an alternative to steel reinforcement, shape memory alloy (SMA)-based reinforcing bars are emerging for improving the seismic performance of concrete bridge piers. This paper presents an assessment of concrete bridge piers with different reinforcement alternatives, namely steel reinforcement, steel-SMA hybrid reinforcement and SMA reinforcement. The bridge piers with different reinforcements are designed having a same lateral resistance, or in other words, the flexural capacities of plastic hinges are designed equal. Based on this, numerical studies are conducted to investigate the relative performance of different bridge piers under seismic loadings. Seismic responses in terms of the maximum drift, residual drift as well as dissipated energy are obtained and compared. The results show that all the three cases with different reinforcements exhibit similar maximum drifts for different earthquake magnitudes. The SMA-reinforced bridge pier has the smallest post-earthquake residual displacement and dissipated energy, whereas the steel-reinforced pier shows the opposite responses. The steel-SMA hybrid reinforcement can achieve a reasonable balance between the residual deformation and energy dissipation.


Author(s):  
B. Y. Ren ◽  
B. Q. Chen

The different Shape Memory Alloy (SMA) actuators have been widely used in the fields of smart structures. However, the accurate prediction of thermomechanical behavior of SMA actuators is very difficult due to the nonlinearity of inherence hysteresis of SMA. Therefore, the tracking control accuracy of SMA actuator is very important for the practical application of the SMA actuator. A dynamic hysteresis model of bias-type SMA actuator based on constitutive law developed by Brinson et al. and hysteresis model developed by Ikuta et al. is presented. The control systems composed of the Proportional Integral Derivative (PID) controller as well as a fuzzy controller or a fuzzy-PID composite controller for compensating the hysteresis is proposed. The effort of tracking control system is analyzed according to the simulation on the displacement of SMA actuator with the three kinds of controllers. The result can provide a reference for the application of SMA actuator in the fields of smart structures.


Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2576
Author(s):  
Alfonso Gómez-Espinosa ◽  
Roberto Castro Sundin ◽  
Ion Loidi Eguren ◽  
Enrique Cuan-Urquizo ◽  
Cecilia D. Treviño-Quintanilla

New actuators and materials are constantly incorporated into industrial processes, and additional challenges are posed by their complex behavior. Nonlinear hysteresis is commonly found in shape memory alloys, and the inclusion of a suitable hysteresis model in the control system allows the controller to achieve a better performance, although a major drawback is that each system responds in a unique way. In this work, a neural network direct control, with online learning, is developed for position control of shape memory alloy manipulators. Neural network weight coefficients are updated online by using the actuator position data while the controller is applied to the system, without previous training of the neural network weights, nor the inclusion of a hysteresis model. A real-time, low computational cost control system was implemented; experimental evaluation was performed on a 1-DOF manipulator system actuated by a shape memory alloy wire. Test results verified the effectiveness of the proposed control scheme to control the system angular position, compensating for the hysteretic behavior of the shape memory alloy actuator. Using a learning algorithm with a sine wave as reference signal, a maximum static error of 0.83° was achieved when validated against several set-points within the possible range.


2019 ◽  
Vol 30 (15) ◽  
pp. 2241-2256 ◽  
Author(s):  
Suchao Li ◽  
Chenxi Mao

Two types of novel shape-memory alloy-based devices with three-dimensional isolation potential and deformation recovery abilities were developed. These two types of isolators, which are called shape-memory alloy pseudo-rubber isolators, were both created with martensitic shape-memory alloy wires through weaving, rolling, and punching processes, but they underwent heat treatment at different fabrication stages and for different durations. A series of mechanical tests were performed on these two types of shape-memory alloy pseudo-rubber isolators to investigate their properties under compression, shear, and combined compression–shear loading at room temperature. The restorable shear limit was then investigated, and the corresponding shear failure mechanism was discussed according to a tension test of one thin layer of the shape-memory alloy wire mesh. Subsequently, the deformation recovery ability of the shape-memory alloy pseudo-rubber isolator with residual deformation was tested through heating on a thermo-control stove. Finally, the mechanical-property stabilities, energy-dissipation abilities, and recovery abilities were compared between the two types of shape-memory alloy pseudo-rubber isolator devices. The experimental results indicated that both types of shape-memory alloy pseudo-rubber isolators had excellent residual deformation recovery abilities, and the type-I shape-memory alloy pseudo-rubber isolator device had more stable mechanical properties than the type-II shape-memory alloy pseudo-rubber isolator. The type-I shape-memory alloy pseudo-rubber isolator device is thus an ideal candidate for traditional three-dimensional isolators.


2021 ◽  
pp. 1061-1071
Author(s):  
Gisha George ◽  
K. R. Bindhu ◽  
Anagha Krishnan Nambissan

2018 ◽  
Vol 30 (2) ◽  
pp. 186-197 ◽  
Author(s):  
Reza Damansabz ◽  
Fathollah Taheri-Behrooz

Shape memory effect of NiTi wires is utilized to design various smart composite structures. In these systems, smart wires can induce strains in the host structure by their inherent shape memory effect and phase transformation at elevated temperatures. This article presents an experimental and numerical study on the actuation capability of shape memory alloy wires embedded in the carbon/epoxy composite. In the experimental part, hybrid shape memory alloy/carbon/epoxy composite specimens are fabricated and examined to measure induced strains in the host structure by the phase transformation of the shape memory alloy wires. Hybrid composite specimens were clamped at one end, and the shape memory alloy wires were activated using electrical resistive heating. Numerical simulations were carried out using ABAQUS software to simulate the actual thermomechanical behavior of the hybrid composite specimens. A three-dimensional finite element model based on cohesive zone modeling is used to predict interfacial debonding in hybrid composite plates. The results of the parametric study suggest that by increasing Young’s modulus of the host composites, the amount of the induced strain decreases rapidly. However, for Young’s moduli more than 20 GPa, the induced strain will stay almost constant. Moreover, it was confirmed that increasing the shape memory alloy pre-strain without controlling the actuation temperature may result in the reduction of induced strain in the host composites.


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