A Method of Reinforcement and Vibration Reduction of Girder Bridges Using Shape Memory Alloy Cables

Bending and torsional vibrations caused by moving vehicle loads are likely to affect the traffic safety and comfort for girder bridges with limited torsional rigidity. This paper studies the use of cables made of shape memory alloy (SMA) as the devices of reinforcement and vibration reduction for girder bridges. The SMA cables are featured by their small volume, expedient installation. To investigate their effect on the vibration of girder bridges, theoretical analysis, numerical simulation and experimental study were conducted in this paper. For bending vibration, the governing equations of the girder with and without SMA cables subjected to moving vehicle loads were derived, while for torsional vibration, the finite element (FE) simulations were used instead. The results of bending and torsional vibrations obtained by the analytical approach and FE simulations, respectively, were compared with the experimental ones from model testing. It was confirmed that the SMA cables can restrain the vibration of the girder bridge effectively.

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06.06: Vibration reduction of steel girder bridges: Using shape memory alloy cables

ce/papers ◽

10.1002/cepa.188 ◽

2017 ◽

Vol 1 (2-3) ◽

pp. 1457-1462

Author(s):

Airong Liu ◽

Chun-Hui Liu ◽

Yong-Lin Pi ◽

Yong-Hui Huang

Keyword(s):

Shape Memory Alloy ◽

Shape Memory ◽

Vibration Reduction ◽

Steel Girder ◽

Girder Bridges ◽

Steel Girder Bridges

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Experimental investigation of vibration reduction using shape memory alloys

Journal of Intelligent Material Systems and Structures ◽

10.1177/1045389x12461696 ◽

2012 ◽

Vol 24 (2) ◽

pp. 247-261 ◽

Cited By ~ 41

Author(s):

Ricardo AA Aguiar ◽

Marcelo A Savi ◽

Pedro MCL Pacheco

Keyword(s):

Dynamical Systems ◽

Shape Memory Alloy ◽

Shape Memory Alloys ◽

Shape Memory ◽

Smart Materials ◽

Experimental Analysis ◽

Vibration Reduction ◽

Dynamical Response ◽

Temperature Variations ◽

Experimental Apparatus

Smart materials have a growing technological importance due to their unique thermomechanical characteristics. Shape memory alloys belong to this class of materials being easy to manufacture, relatively lightweight, and able to produce high forces or displacements with low power consumption. These aspects could be exploited in different applications including vibration control. Nevertheless, literature presents only a few references concerning the experimental analysis of shape memory alloy dynamical systems. This contribution deals with the experimental analysis of shape memory alloy dynamical systems by considering an experimental apparatus consisted of low-friction cars free to move in a rail. A shaker that provides harmonic forcing excites the system. The vibration analysis reveals that shape memory alloy elements introduce complex behaviors to the system and that different thermomechanical loadings are of concern showing the main aspects of the shape memory alloy dynamical response. Special attention is dedicated to the analysis of vibration reduction that can be achieved by considering different approaches exploiting either temperature variations promoted by electric current changes or vibration absorber techniques. The results establish that adaptability due to temperature variations is defined by a competition between stiffness and hysteretic behavior changes.

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A tuned vibration absorber constituted of shape memory alloy wires for vibration reduction of platform structures: design and implementation

MATEC Web of Conferences ◽

10.1051/matecconf/201818500013 ◽

2018 ◽

Vol 185 ◽

pp. 00013

Author(s):

Yun-Ting Liao ◽

Jia-Hong Lin ◽

Chun-Ying Lee

Keyword(s):

Shape Memory Alloy ◽

Shape Memory ◽

High Efficiency ◽

Vibration Reduction ◽

Vibration Absorber ◽

Practical Applications ◽

Operation Conditions ◽

Tunable Frequency ◽

Six Degree Of Freedom ◽

Tuned Vibration Absorber

Machinery can suffer from mechanical vibrations since resonance may be generated from time-varying external excitations under different operation conditions. These detrimental vibrations may significantly influence the device's performance, effectiveness and reliability in operation. In this paper, an innovative, simple and high-efficiency tuned vibration absorber (TVA) consisting of shape memory alloy (SMA) wires, which is referred to a wire-type tuned vibration absorber (WTVA), is proposed to reduce the induced vibration. Experiments are carried out using a six-degree-of-freedom platform which is designed to simulate the frame of precision machinery in practical applications. With the equivalent stiffness of SMA wires adjusted by the controlled electric current, the frequency tunability of WTVA can be achieved. When the natural frequency of WTVA tuned in with the disturbance frequency, the experimental results demonstrate that the efficiency in vibration reduction of the platform is drastically increased even with considerable weight difference between WTVA and the platform. Moreover, the tunable frequency span also increases greatly due to the new design of WTVA and the material characteristics of SMA wires.

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Mathematical Model of a Shape Memory Alloy Spring Intended for Vibration Reduction Systems

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.177.65 ◽

2011 ◽

Vol 177 ◽

pp. 65-75 ◽

Cited By ~ 8

Author(s):

Waldemar Rączka ◽

Jarosław Konieczny ◽

Marek Sibielak

Keyword(s):

Mathematical Model ◽

Shape Memory Alloy ◽

Shape Memory ◽

Vibration Reduction ◽

Spring Model ◽

Response Characteristics ◽

Dynamics And Control ◽

Active Vibration ◽

Sma Spring ◽

Energy Accumulation And Dissipation

The article discusses a prototype of a Shape Memory Alloy (SMA) spring intended for controlled vibration reduction systems. The spring has been subject to experiments and the article presents selected static and dynamic characteristics. The experiments were conducted at the Dynamics and Control of Structures Laboratory of the AGH University of Science and Technology. They permitted the formulation of a mathematical model for the SMA spring. The model takes into account the phenomena of energy accumulation and dissipation. The parameters of the spring model have been determined, based on the experimental data. The model takes into account the relationship of stiffness and damping to alloy temperature and the frequency of excitation. It has been demonstrated that the properties of the spring may be altered under controlled conditions. The spring model was then used in simulations. They served as the basis for the determination of the frequency response characteristics, which were then compared to the characteristics of a real spring. The mathematical model developed may be applied in the design of passive, semi-active, and active vibration reduction systems, as well as in the synthesis of adaptive smart vibration reduction systems.

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A Soft Haptic Glove Actuated with Shape Memory Alloy and Flexible Stretch Sensors

Sensors ◽

10.3390/s21165278 ◽

2021 ◽

Vol 21 (16) ◽

pp. 5278

Author(s):

Silvia Terrile ◽

Jesus Miguelañez ◽

Antonio Barrientos

Keyword(s):

Finite Element ◽

Virtual Reality ◽

Shape Memory Alloy ◽

Shape Memory ◽

Hand Movement ◽

Hand Position ◽

Proper Functioning ◽

Fe Simulations ◽

Haptic Technology ◽

Kinesthetic Perception

Haptic technology allows us to experience tactile and force sensations without the need to expose ourselves to specific environments. It also allows a more immersive experience with virtual reality devices. This paper presents the development of a soft haptic glove for kinesthetic perception. It is lightweight and soft to allow for a more natural hand movement. This prototype actuates two fingers with two shape memory alloy (SMA) springs. Finite element (FE) simulations of the spring have been carried out to set the dimensions of the actuators. Flexible stretch sensors provide feedback to the system to calculate the tension of the cables attached to the fingers. The control can generate several recognizable levels of force for any hand position since the objects to be picked up can vary in weight and dimension. The glove can generate three levels of force (100, 200 and 300 g) to evaluate more easily the proper functioning. We realized tests on 15 volunteers simulating forces in various order after a quick training. We also asked volunteers about the experience for comfort, global experience and simplicity). Results were satisfactory in both aspects: the glove fulfilled its function, and the users were comfortable with it.

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Development of a Reference-Free Indirect Bridge Displacement Sensing System

Sensors ◽

10.3390/s21165647 ◽

2021 ◽

Vol 21 (16) ◽

pp. 5647

Author(s):

Jongbin Won ◽

Jong-Woong Park ◽

Junyoung Park ◽

Junsik Shin ◽

Minyong Park

Keyword(s):

Estimation Method ◽

Reference Points ◽

Maximum Displacement ◽

Moving Vehicle ◽

Displacement Estimation ◽

Sensing System ◽

Girder Bridges ◽

Sensor Platform ◽

Load Carrying ◽

Vehicle Loads

Bridge displacement measurements are important data for assessing the condition of a bridge. Measuring bridge displacement under moving vehicle loads is helpful for rating the load-carrying capacity and evaluating the structural health of a bridge. Displacements are conventionally measured using a linear variable differential transformer (LVDT), which needs stable reference points and thus prohibits the use of this method for measuring displacements for bridges crossing sea channels, large rivers, and highways. This paper proposes a reference-free indirect bridge displacement sensing system using a multichannel sensor board strain and accelerometer with a commercial wireless sensor platform (Xnode). The indirect displacement estimation method is then optimized for measuring the structural displacement. The performance of the developed system was experimentally evaluated on concrete- and steelbox girder bridges. In comparison with the reference LVDT data, the maximum displacement error for the proposed method was 2.17%. The proposed method was successfully applied to the displacement monitoring of a tall bridge (height = 20 m), which was very difficult to monitor using existing systems.

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Flexure-Based Active Needle for Enhanced Steering Within Soft Tissue

Journal of Medical Devices ◽

10.1115/1.4030654 ◽

2015 ◽

Vol 9 (4) ◽

Cited By ~ 5

Author(s):

Naresh V. Datla ◽

Parsaoran Hutapea

Keyword(s):

Soft Tissue ◽

Shape Memory Alloy ◽

Minimally Invasive ◽

Shape Memory ◽

Torsional Rigidity ◽

Axial Rotation ◽

Needle Insertion ◽

Wire Diameter ◽

Pig Liver ◽

Target Locations

Flexible needles with enhanced steerability are desired in minimally invasive surgeries to reach target locations precisely and to bypass critical organs lying in the planned path. We have proposed a flexure-based active needle that enhances steerability by using a flexure element near the needle tip. Needle curvature is controlled by attached shape memory alloy (SMA) wires that apply actuator forces to bend the needle. Using actuator forces rather than axial rotation to control needle curvature minimizes placement errors due to torsional rigidity that is compromised by the flexure element. A prototype of the proposed needle was developed and was demonstrated in air, in tissue-mimicking gel, and in pig liver. Needle insertion studies with the prototype showed that increasing the wire diameter from 0.15 to 0.24 mm insignificantly affected the maximum needle tip deflection (19.4±0.3 mm for 150 mm insertion), but significantly increased the actuation current (from 0.60 to 1.04 A).

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