scholarly journals Recentering Shape Memory Alloy Passive Damper for Structural Vibration Control

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Hui Qian ◽  
Hongnan Li ◽  
Gangbing Song ◽  
Wei Guo
Keyword(s):  
Energy Dissipation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Structural Control ◽  
Structural Response ◽  
Time History ◽  
Nonlinear Time History Analysis ◽  
Structural Vibration ◽  
Seismic Protection ◽  
Building Structures

This paper presents a preliminary study on the evaluation of an innovative energy dissipation system with shape memory alloys (SMAs) for structural seismic protection. A recentering shape memory alloy damper (RSMAD), in which superelastic nitinol wires are utilized as energy dissipation components, is proposed. Improved constitutive equations based on Graesser and Cozzarelli model are proposed for superelastic nitinol wires used in the damper. Cyclic tensile-compressive tests on the damper with various prestrain under different loading frequencies and displacement amplitudes were conducted. The results show that the hysteretic behaviors of the damper can be modified to best fit the needs for passive structural control applications by adjusting the pretension of the nitinol wires, and the damper performance is not sensitive to frequencies greater than 0.5 Hz. To assess the effectiveness of the dampers for structural seismic protection, nonlinear time history analysis on a ten-story steel frame with and without the dampers subjected to representative earthquake ground motions was performed. The simulation results indicate that superelastic SMA dampers are effective in mitigating the structural response of building structures subjected to strong earthquakes.

Mitigation of Vertical and Horizontal Seismic Excitations on Bridges Utilizing Shape Memory Alloy System

2013 ◽  
Vol 831 ◽  
pp. 90-94 ◽  
Author(s):  
H. Aryan ◽  
M. Ghassemieh
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Three Dimensional ◽  
Time History ◽  
Alloy System ◽  
Practical Method ◽  
Nonlinear Time History Analysis ◽  
Vertical Acceleration ◽  
Three Dimensional Model ◽  
Seismic Excitations

Vertical seismic excitation has a tremendous effect on bridges and many researchers have pointed out bridges damages occurred during the past significant earthquakes which were direct results of ignoring vertical acceleration of ground motions. Many studies have emphasized the importance of extending practical methods to reduce effects of vertical acceleration of earthquakes besides effects of horizontal accelerations; but no practical method has proposed up to now. In this article, an innovative shape memory alloy system is proposed for bridges that can simultaneously controls effects of vertical and horizontal seismic excitations on bridge and reduce them. To evaluate the effectiveness of the shape memory alloy system, a nonlinear time history analysis is conducted on a detailed three-dimensional model of a multi-span simply supported bridge using a representative ground motion. The results show that the proposed new system is very effective for reducing effects of vertical and horizontal seismic excitations on bridges.

Study on Structural Vibration Control by Using Shape Memory Alloy

2009 ◽  
Vol 417-418 ◽  
pp. 229-232 ◽  
Author(s):  
Bo Zhou ◽  
Yan Ju Liu ◽  
Guang Ping Zou ◽  
Jin Song Leng
Keyword(s):  
Phase Transformation ◽  
Energy Dissipation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Passive Control ◽  
Transformation Model ◽  
Basic Knowledge ◽  
Structural Vibration ◽  
Beam Structure ◽  
Structural Vibration Control

Shape memory alloy is a good candidate for realizing the passive control of structural vibration due to its excellent characteristic of energy dissipation. In this paper, the damping characteristic of shape memory alloy is quantitatively described based on Liang’s phase transformation model and thermo-mechanical constitutive equation for shape memory alloy. The vibration performances of a beam structure with shape memory alloy damper are investigated based on basic knowledge of vibration theorem. Numerical calculations show that the vibration of beam structure is well reduced by using the shape memory alloy damper.

scholarly journals Life-cycle cost evaluation of steel structures retrofitted with steel slit damper and shape memory alloy–based hybrid damper

2018 ◽  
Vol 22 (1) ◽  
pp. 3-16 ◽  
Author(s):  
Mohamed NourEldin ◽  
Asad Naeem ◽  
Jinkoo Kim
Keyword(s):  
Life Cycle ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Life Cycle Cost ◽  
Time History ◽  
Steel Structures ◽  
Cost Evaluation ◽  
Nonlinear Time History Analysis ◽  
Analysis Model ◽  
Hybrid Damper

In this study, the seismic capacity of a hybrid damper, composed of a steel slit plate damper and two shape memory alloy bars, is investigated through fragility analysis and life-cycle cost evaluation of a steel frame retrofitted with the damper. The nonlinear time history analysis model frames show that the seismic responses of the frames equipped with hybrid damper are significantly lesser than the frames retrofitted with conventional slit dampers. The enhancement in the seismic performance of frames retrofitted with hybrid damper is because of extra stiffness, energy dissipation, and self-centering capability provided by the shape memory alloy bars. It is also observed that the life-cycle cost of the frames equipped with hybrid dampers is smallest compared with the life-cycle cost of the bare frames and the frames equipped with slit dampers, even though the initial cost is of the hybrid damper is higher than that of the conventional slit damper.

Progress on Study and Application of Shape Memory Alloy in Passive Energy Dissipation

2012 ◽  
Vol 198-199 ◽  
pp. 3-8
Author(s):  
Yu Hong Ling ◽  
Hong Hua Ling
Keyword(s):  
Energy Dissipation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Structural Vibration ◽  
Application Research ◽  
Structural Vibration Control ◽  
The Past ◽  
Passive Energy Dissipation ◽  
Passive Devices ◽  
Unique Shape

Shape memory alloy (SMA) has a good application prospect in structural vibration control due to its unique shape memory effect and superelasticity. First, the characteristics of SMA is briefly introduced. This paper then reviews research results on SMA for passive energy dissipation in the past decades, including development of different mechanisms of SMA-based passive devices and their performance tests and application research. Finally, application of SMA for passive energy dissipation is prospected.

Seismic Vibration Control Using Superelastic Shape Memory Alloys

2006 ◽  
Vol 128 (3) ◽  
pp. 294-301 ◽  
Author(s):  
Jason McCormick ◽  
Reginald DesRoches ◽  
Davide Fugazza ◽  
Ferdinando Auricchio
Keyword(s):  
Shape Memory ◽  
Structural Control ◽  
Time History ◽  
Nonlinear Time History Analysis ◽  
Small Scale ◽  
Niti Shape Memory Alloy ◽  
Braced Frames ◽  
History Analysis ◽  
Bracing System ◽  
Nonlinear Time History

Superelastic NiTi shape memory alloy (SMA) wires and bars are studied to determine their damping and recentering capability for applications in the structural control of buildings subjected to earthquake loadings. These studies improve the knowledge base in regard to the use of SMAs in seismic design and retrofit of structures. The results show that the damping properties of austenitic SMAs are generally low. However, the residual strain obtained after loading to 6% strain is typically <0.75%. In general, it is shown that large diameters bars perform as well as wire specimens used in non-civil-engineering applications. The results of a small-scale shake table test are then presented as a proof of concept study of a SMA cross-bracing system. These results are verified through analytical nonlinear time history analysis. Finally, a three-story steel frame implementing either a traditional steel buckling-allowed bracing system or a SMA bracing system is analyzed analytically to determine if there is an advantage to using a SMA bracing system. The results show that the SMA braces improve the response of the braced frames.

Seismic retrofit of precast soft-storey building using diagonal steel-shape memory alloy bracing device: Numerical investigation

2018 ◽  
Vol 22 (3) ◽  
pp. 802-817 ◽  
Author(s):  
Xiaoxian Liu ◽  
Hing-Ho Tsang ◽  
John L Wilson
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Tensile Force ◽  
Time History ◽  
Seismic Retrofitting ◽  
Nonlinear Time History Analysis ◽  
Building Frame ◽  
Soft Storey ◽  
Steel Shape ◽  
Storey Building

A diagonal steel-shape memory alloy bracing device is proposed for seismic retrofitting of vulnerable building frame structure. Superelastic shape memory alloy bar is put in series with steel bars in the bracing. The device makes use of the loading plateau of superelastic shape memory alloy to limit the tensile force of diagonal bracing. A precast soft-storey building frame in Australia was selected for a case study. A numerical model of the frame was developed and validated with the results from full-scale pull-down field tests. Nonlinear time history analysis was then conducted to evaluate the seismic performance of the frame with different retrofitting strategies. The result shows that the diagonal steel-shape memory alloy bracing can reduce the displacement demand on the soft-storey frame. Meanwhile, the level of tensile force of steel-shape memory alloy bracing can be controlled by the force plateau of the shape memory alloy bar, which is recommended to be 20% of the yielding force of the steel bar. The lower tensile force demand could alleviate the force demand at the associated support connections.

scholarly journals Experimental and Numerical Analysis of the Mechanical Properties of a Pretreated Shape Memory Alloy Wire in a Self-Centering Steel Brace

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 80
Author(s):  
Bo Zhang ◽  
Sizhi Zeng ◽  
Fenghua Tang ◽  
Shujun Hu ◽  
Qiang Zhou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Energy Dissipation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Loading Rate ◽  
Effective Elastic Modulus ◽  
Maximum Energy ◽  
Numerical Results ◽  
Energy Dissipation Capacity

As a stimulus-sensitive material, the difference in composition, fabrication process, and influencing factors will have a great effect on the mechanical properties of a superelastic Ni-Ti shape memory alloy (SMA) wire, so the seismic performance of the self-centering steel brace with SMA wires may not be accurately obtained. In this paper, the cyclic tensile tests of a kind of SMA wire with a 1 mm diameter and special element composition were tested under multi-working conditions, which were pretreated by first tensioning to the 0.06 strain amplitude for 40 cycles, so the mechanical properties of the pretreated SMA wires can be simulated in detail. The accuracy of the numerical results with the improved model of Graesser’s theory was verified by a comparison to the experimental results. The experimental results show that the number of cycles has no significant effect on the mechanical properties of SMA wires after a certain number of cyclic tensile training. With the loading rate increasing, the pinch effect of the hysteresis curves will be enlarged, while the effective elastic modulus and slope of the transformation stresses in the process of loading and unloading are also increased, and the maximum energy dissipation capacity of the SMA wires appears at a loading rate of 0.675 mm/s. Moreover, with the initial strain increasing, the slope of the transformation stresses in the process of loading is increased, while the effective elastic modulus and slope of the transformation stresses in the process of unloading are decreased, and the maximum energy dissipation capacity appears at the initial strain of 0.0075. In addition, a good agreement between the test and numerical results is obtained by comparing with the hysteresis curves and energy dissipation values, so the numerical model is useful to predict the stress–strain relations at different stages. The test and numerical results will also provide a basis for the design of corresponding self-centering steel dampers.

scholarly journals Numerical Modeling of Unreinforced Masonry Walls Strengthened with Fe-Based Shape Memory Alloy Strips

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2961
Author(s):  
Moein Rezapour ◽  
Mehdi Ghassemieh ◽  
Masoud Motavalli ◽  
Moslem Shahverdi
Keyword(s):  
Energy Dissipation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Unreinforced Masonry ◽  
Masonry Wall ◽  
Masonry Walls ◽  
Vertical Strip ◽  
Maximum Resistance ◽  
The Cross ◽  
Post Tensioning

This study presents a new way to improve masonry wall behavior. Masonry structures comprise a significant part of the world’s structures. These structures are very vulnerable to earthquakes, and their performances need to be improved. One way to enhance the performances of such types of structures is the use of post-tensioning reinforcements. In the current study, the effects of shape memory alloy as post-tensioning reinforcements on originally unreinforced masonry walls were investigated using finite element simulations in Abaqus. The developed models were validated based on experimental results in the literature. Iron-based shape memory alloy strips were installed on masonry walls by three different configurations, namely in cross or vertical forms. Seven macroscopic masonry walls were modeled in Abaqus software and were subjected to cyclic loading protocol. Parameters such as stiffness, strength, durability, and energy dissipation of these models were then compared. According to the results, the Fe-based strips increased the strength, stiffness, and energy dissipation capacity. So that in the vertical-strip walls, the stiffness increases by 98.1%, and in the cross-strip model's position, the stiffness increases by 127.9%. In the vertical-strip model, the maximum resistance is equal to 108 kN, while in the end cycle, this number is reduced by almost half and reaches 40 kN, in the cross-strip model, the maximum resistance is equal to 104 kN, and in the final cycle, this number decreases by only 13.5% and reaches 90 kN. The scattering of Fe-based strips plays an important role in energy dissipation. Based on the observed behaviors, the greater the scattering, the higher the energy dissipation. The increase was more visible in the walls with the configuration of the crossed Fe-based strips.

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