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.

Analytical investigation of the behavior of a new smart recentering shear damper under cyclic loading

2019 ◽  
Vol 31 (4) ◽  
pp. 550-569 ◽  
Author(s):  
Nadia M Mirzai ◽  
Reza Attarnejad ◽  
Jong Wan Hu
Keyword(s):  
Energy Dissipation ◽  
Cyclic Loading ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Passive Control ◽  
Shear Failure ◽  
Low Cost ◽  
Residual Deformation ◽  
Friction Damper ◽  
Element Analysis

Shear recentering polyurethane friction damper is a type of passive control device, including the shape memory alloy plates, polyurethane springs, and friction devices. This damper can be employed in the shear link of an inverted Y-shaped braced frame. As the failure mode is a shear failure, in this study, the shear recentering polyurethane friction damper is proposed to remove the residual deformation of the structure that remains after a strong earthquake and causes considerable damage to the structure. The shear recentering polyurethane friction damper can help the structure to return to the initial position. Furthermore, as compared to many other dampers, this new damper is of low cost, and its assembling requires a simple technology. In order to evaluate the performance of the damper, four different cases are considered. Furthermore, the effect of each component is investigated in each case, and a finite element analysis is performed under cyclic loading using the ABAQUS platform. In addition, for the sake of comparison, the shape memory alloy plates are replaced by steel ones, and a comparison for the results demonstrates that the recentering shear dampers can significantly decrease residual deformation, while there is a large amount of residual deformation in the steel damper. Due to using the polyurethane springs, the ultimate capacity of the shear shape memory alloy polyurethane friction damper is 500 kN; however, in the shear steel polyurethane friction damper, it is only about 300 kN. Furthermore, the energy dissipation by the shear shape memory alloy polyurethane friction damper is larger than the shear steel polyurethane friction damper. The results show that the steel plates cannot effectively increase energy dissipation.

Finite Element Analysis of Removable Shape Memory Alloy Pipe Joint’s Cone Sealing Performance

2015 ◽  
Vol 817 ◽  
pp. 685-689
Author(s):  
Bin Zhou ◽  
Fu Shun Liu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Contact Stress ◽  
Structural Parameters ◽  
Cone Angle ◽  
Element Analysis ◽  
Sealing Performance ◽  
The Finite Element Analysis

According to the behavior of shape memory alloys, a structure of removable shape memory alloy pipe joint was designed. The contact manner of two parts of this structure is cone-globe. Cone-globe sealing is the key point of this structure’s sealing. Therefore the finite element analysis software ANSYS was used to simulate and calculate the sealing. The result shows that the width of the sealing surface and the contact stress altered with the change of structural parameters, which affected the sealing most. According to the value of the sealing surface’s width and the contact stress, the structural parameters including cone angle can be definitely settled.

A model for shape memory alloy beams accounting for tensile compressive asymmetry

2019 ◽  
Vol 30 (18-19) ◽  
pp. 2697-2715 ◽  
Author(s):  
Nguyen Van Viet ◽  
Wael Zaki ◽  
Ziad Moumni
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Solid Phase ◽  
Constitutive Relations ◽  
Beam Theory ◽  
Element Analysis ◽  
Proposed Model ◽  
The Finite Element Analysis ◽  
Tension And Compression ◽  
Asymmetric Shape

A new analytical model is derived for cantilever beams made from superelastic shape memory alloy and subjected to tip load. The deformation of the beam is described based on Timoshenko beam theory using constitutive relations that account for asymmetric shape memory alloy response in tension and compression. Analytical moment and shear force equations are developed and the position of the neutral axis and the different solid phase regions in the beam are tracked throughout a full loading–unloading cycle. Validation of the proposed model is carried out against data from the literature and from the finite element analysis considering tensile–compressive asymmetry in shape memory alloy behavior.

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.

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.

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