PROGRESS ON THE DEVELOPMENT OF SHAPE-MEMORY-ALLOY METACOMPOSITES

2021 ◽  
Author(s):  
DUSAN MILOSAVLJEVIC ◽  
QIANLONG ZHANG ◽  
MARCO MOSENEDER ◽  
HONGFEI ZHU ◽  
NORA LECIS ◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Composite Structures ◽  
Dynamic Properties ◽  
Research Effort ◽  
Mechanical Energy ◽  
Engineering Application ◽  
Operating Conditions ◽  
Development Effort

Shape memory alloys (SMA) have long been explored as a semi-passive approach to mechanical energy dissipation particularly, but not exclusively, for application to vibration control. More recently, the integration of SMAs in composite materials has opened the opportunity to synthesize tunable composite structures exhibiting significantly enhanced energy dissipation characteristics and a certain degree of adaptability to different operating conditions. Despite the significant progress in the development and manufacturing of SMAs over the past several decades, the cost of common Ni-based alloys has remained an important factor hindering their widespread engineering application. The long-term goal of this research effort is to model, design, and fabricate shape-memory-alloy (SMA) meta-composites employing lower volume fractions of a more affordable Cu-based alloy, while still enabling enhanced and tunable dynamic properties. This paper summarizes recent progress in the development of the meta-composite platform and focuses on aspects involving both numerical modeling and fabrication of SMA materials. On the modeling side, particular emphasis is given to assess the ability to tune the dynamic performance of continuous SMA structures by exploiting the different phases and transformations of the alloy. On the other side, the material development effort focuses on the identification of the optimal chemical composition, mechanical and heat treatment processes. A combination of numerical and experimental results is presented to illustrate capabilities and opportunities presented by this material platform.

Experimental Study on Mechanical Properties of Large NiTi Superelastic Shape Memory Alloy Bars

2021 ◽  
Author(s):  
Qiujun Ning ◽  
Lihua Zhu ◽  
Wei Han ◽  
Cheng Zhao
Keyword(s):  
Mechanical Properties ◽  
Energy Dissipation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Mechanical Performance ◽  
Engineering Application ◽  
Test Results ◽  
Equivalent Viscous Damping ◽  
Heat Treated ◽  
Strength And Stiffness

Abstract This study intensively examined the mechanical properties of large-sized superelastic shape memory alloy (SMA) bars, mainly focusing on their self-centering and energy dissipation capabilities. A detailed investigation on the effects of the heat treatment strategy, loading rate, strain amplitude, cyclic loading, prestress, and diameter of the SMA bars on their mechanical performance—residual strain, energy dissipation, equivalent viscous damping ratios, strength, and stiffness—was conducted. Furthermore, the fracture microstructure of monotonic tensile specimens was analyzed via scanning electron microscopy. The results indicated that the optimally heat-treated SMA bars show good superelasticity. The mechanical properties were relatively stable under constant strain loading–unloading training, which should be considered in engineering applications. The test results provided basic experimental data support for the engineering application of large SMA bars.

Study on Hysteretic Energy Dissipation of SMA Wires, Bars and Plates

2011 ◽  
Vol 243-249 ◽  
pp. 5339-5342
Author(s):  
Ji Gang Zhang ◽  
Yan Mei Liu ◽  
Jing Jing Zhang ◽  
Ke Yong Gao
Keyword(s):  
Energy Dissipation ◽  
Cyclic Loading ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Engineering Application ◽  
Tensile Tests ◽  
The Other ◽  
Test Results ◽  
Hysteretic Energy ◽  
Better Than

Through tensile tests of shape memory alloy(SMA)wires,bars and plates, this paper analyzes hysteretic energy-dissipating capacities of thesesmartSMA materials in cyclic loading conditions. According to the test results, this article demonstrates the influence on energy dissipating capacity of SMA wires,bars and plates by different strain amplitudes, loading frequencies, cyclic numbers and pre-strains, then obtains change rules of hysteretic energy-dissipation.The test results show that the SMA wires is better than the other two SMA bars and plates, the SMA wires, bars and plates had better to be trainingbefore civil engineering application.

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.

Experimental Validation and Numerical Simulation of Shape Memory Flat Wire Actuators

2014 ◽  
Author(s):  
Alexander Czechowicz ◽  
Sven Langbein
Keyword(s):  
Shape Memory Alloy ◽  
Boundary Conditions ◽  
Shape Memory ◽  
Smart Materials ◽  
Empirical Data ◽  
Dynamic Properties ◽  
Fatigue Behavior ◽  
Different Boundary Conditions ◽  
Heating And Cooling ◽  
Actual Shape

Shape memory alloys (SMA) are thermally activated smart materials. Due to their ability to change into a previously imprinted actual shape through the means of thermal activation, they are suitable as actuators for mechatronical systems. Despite of the advantages shape memory alloy actuators provide, these elements are only seldom integrated by engineers into mechatronical systems. Reasons are the complex characteristics, especially at different boundary conditions and the missing simulation- and design tools. Also the lack of knowledge and empirical data are a reason why development projects with shape memory actuators often lead to failures. This paper deals with the dynamic properties of SMA-actuators (Shape Memory Alloy) — characterized by their rate of heating and cooling procedures — that today can only be described insufficiently for different boundary conditions. Based on an analysis of energy fluxes into and out of the actuator, a numerical model of flat-wire used in a bow-like structure, implemented in MATLAB/SIMULINK, is presented. Different actuation parameters, depending on the actuator-geometry and temperature are considered in the simulation in real time. Additionally this publication sums up the needed empirical data (e.g. fatigue behavior) in order to validate the numerical two dimensional model and presents empirical data on SMA flat wire material.

The cyclic response of circular reinforced concrete column to foundation connections strengthened with shape memory alloy bars

2020 ◽  
pp. 002199832096144
Author(s):  
Mahdieh Miralami ◽  
M Reza Esfahani ◽  
Mohammadreza Tavakkolizadeh ◽  
Reza Khorramabadi ◽  
Jalil Rezaeepazhand
Keyword(s):  
Energy Dissipation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Load Capacity ◽  
Lateral Load ◽  
Reference Specimen ◽  
Initial Stiffness ◽  
Residual Displacement ◽  
Cfrp Sheets ◽  
Column Foundation

This study presents a new method for strengthening the circular reinforced concrete (RC) column to foundation connections with shape memory alloy (SMA) bars and carbon fiber reinforced polymer (CFRP) sheets. In the experimental part of the study, three specimens of RC column-foundation connections were cast and tested. One specimen was used as the reference specimen without strengthening. Two other specimens were strengthened with longitudinal SMA bars and CFRP sheets. These specimens were under a constant axial compressive load and cyclic lateral displacements, simultaneously. Next, initial stiffness, energy dissipation capacity, lateral load capacity, ductility, and residual displacement of the specimens were investigated. Due to the superelastic behavior of SMA bars, the residual displacement of column-foundation connections was considerably less than that of the reference specimen. Compared to the reference specimen, the SMA-strengthened and SMA-CFRP-strengthened connections recovered 71.59% and 76.57% of the residual displacement. Therefore, SMA bars were able to recover residual displacements under cyclic loading. Also, the combination of the SMA bars with CFRP sheet was a promising solution for enhancing the amount of the energy dissipation, lateral load capacity, initial stiffness, and ductility parameters. Compared to the reference specimen, the energy dissipation, lateral load capacity, initial stiffness, and ductility ratio parameters of SMA-CFRP-strengthened connection increased about 43.45%, 76.20%, 81.69%, and 242.45%, respectively. In the numerical part of the study, a subroutine was applied for modeling the SMA materials. For the analysis, this subroutine was linked with ABAQUS software. The numerical results showed a close correlation with the experimental results.

11.65: An axial type self-centering energy dissipation device with shape memory alloy for seismic mitigation

ce/papers ◽  
2017 ◽  
Vol 1 (2-3) ◽  
pp. 3356-3364
Author(s):  
Ran Li ◽  
Ganping Shu ◽  
Zhen Liu ◽  
Xiao Lyu ◽  
Meihe Chen
Keyword(s):  
Energy Dissipation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Seismic Mitigation

Experimental Research of PFD-SMA Support System

2011 ◽  
Vol 71-78 ◽  
pp. 4521-4524 ◽  
Author(s):  
Ji Gang Zhang ◽  
Yan Mei Liu ◽  
Yuan Feng Gao ◽  
Jian Han
Keyword(s):  
Energy Dissipation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Support System ◽  
Load Force ◽  
Element Analysis ◽  
Test Study ◽  
Force Increase ◽  
The Finite Element Analysis ◽  
Good Energy

Pall-typed dampers(PFD) have good energy dissipation, and shape memory alloy(SMA) brace has good super-elastic performance, so the PFD-SMA support system is put forward. Through the test study of PFD-SMA support system, analyze the influence to its hysteretic characteristic by preload force of Pall-typed frictional damper, the stiffness and length parameters of shape memory alloy support. The test results show that PFD-SMA support system s have good energy dissipation and good reposition due to its super-elastic performance, with pre-load force increase, its super-elastic performance acts better, its hysteretic curve show super-elastic performance too, and it verifies the correctness of the finite element analysis.

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