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

2011 ◽  
Vol 177 ◽  
pp. 65-75 ◽  
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.

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

2017 ◽  
Vol 17 (07) ◽  
pp. 1750076 ◽  
Author(s):  
Ai-Rong Liu ◽  
Chun-Hui Liu ◽  
Ji-Yang Fu ◽  
Yong-Lin Pi ◽  
Yong-Hui Huang ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Traffic Safety ◽  
Torsional Rigidity ◽  
Vibration Reduction ◽  
Torsional Vibrations ◽  
Moving Vehicle ◽  
Girder Bridges ◽  
Fe Simulations ◽  
Vehicle Loads

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.

scholarly journals Development of Subcarangiform Bionic Robotic Fish Propelled by Shape Memory Alloy Actuators

2021 ◽  
Vol 71 (1) ◽  
pp. 94-101
Author(s):  
M. Muralidharan ◽  
I.A. Palani
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Kinematic Model ◽  
Open Loop ◽  
Robotic Fish ◽  
Water Medium ◽  
Light Weight ◽  
Caudal Fin ◽  
Locomotion Pattern ◽  
Sma Spring

In this paper, a shape memory alloy (SMA) actuated subcarangiform robotic fish has been demonstrated using a spring based propulsion mechanism. The bionic robotic fish developed using SMA spring actuators and light weight 3D printed components can be employed for under water applications. The proposed SMA spring-based design without conventional motor and other rotary actuators was able to achieve two-way shape memory effect and has reproduced the subcarangiform locomotion pattern. The positional kinematic model has been developed and the dynamics of the proposed mechanism were analysed and simulated using Automated Dynamic Analysis of Mechanical Systems (ADAMS). An open loop Arduino-relay based switching control has been adopted to control the periodic actuation of the SMA spring mechanism. The undulation of caudal fin in air and water medium has been analysed. The caudal fin and posterior body of the developed fish prototype have taken part in undulation resembling subcarangiform locomotion pattern and steady swimming was achieved in water with a forward velocity of 24.5 mm/s. The proposed design is scalable, light weight and cost effective which may be suitable for underwater surveillance application.

Design of a 2 DOF Shape Memory Alloy Actuator Using SMA Springs

2021 ◽  
Author(s):  
Hussein F. M. Ali ◽  
Youngshik Kim
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Open Loop ◽  
Degree Of Freedom ◽  
Biologically Inspired ◽  
Loop Control ◽  
Actuator System ◽  
Sma Actuator ◽  
Sma Spring ◽  
Two Degree Of Freedom

Abstract In this paper, we developed two degree of freedom shape memory alloy (SMA) actuator using SMA springs. This module can be applied easily to various applications: device holder, artificial finger, grippes, fish robot, and many other biologically inspired applications, where small size and small wight of the actuator are very critical. This actuator is composed of two sets of SMA springs: one set is for the rotation around the X axis (roll angle) and the other set is for the rotation around the Y axis (pitch angle). Each set contains two elements: one SMA spring and one antagonistic SMA spring. We used an inertia sensor (IMU) and two potentiometers for angles feedback. The SMA actuator system is modeled mathematically and then tested experimentally in open-loop and closed-loop control. We designed and experimentally tuned a proportional integrator derivative (PID) controller to follow the set points and to track the desired trajectories. The main goal of the presented controller is to control roll and pitch angles simultaneously in order to satisfy set points and trajectories within the work space. The experimental results show that the two degree of freedom SMA actuator system follows the desired setpoints with acceptable rise time and overshoot.

Optimal H∞ Control of Structural Vibrations Using Shape Memory Alloy Actuators

1999 ◽  
Author(s):  
Jian Sun ◽  
Ali R. Shahin
Keyword(s):  
Mathematical Model ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Model Uncertainty ◽  
High Frequency ◽  
Structural Vibrations ◽  
Design Procedures ◽  
Sma Actuators ◽  
Temperature Dynamics ◽  
The Mathematical Model

Abstract This paper investigates robust control problem of structural vibrations using shape memory alloy (SMA) wires as actuators. The mathematical model for these SMA actuators is derived with emphasis in model uncertainty. The linearization of the relation between stress and temperature dynamics of SMA actuators is analyzed for active control. To handle the uncertainties caused by the linearization and the neglected high frequency dynamics, optimal H∞ control was employed to design a controller. An example is used to demonstrate the design procedures and the control system is tested in a nonlinear environment.

Discrete Preisach Model of a Shape Memory Alloy Actuator

2016 ◽  
Vol 248 ◽  
pp. 227-234
Author(s):  
Waldemar Rączka ◽  
Jarosław Konieczny ◽  
Marek Sibielak ◽  
Janusz Kowal
Keyword(s):  
Mathematical Model ◽  
Shape Memory Alloy ◽  
Parameter Identification ◽  
Shape Memory ◽  
Preisach Model ◽  
Discrete Form ◽  
Nonlinear Characteristics ◽  
Shape Memory Alloy Actuator ◽  
Sma Actuator ◽  
Identification Model

Shape Memory Alloy is a material used to designing actuators. These actuators have many advantages. They are light, strong and silent. They are building in laboratory and tested because beside advantages they have disadvantages too. SMA actuators have nonlinear characteristics with hysteresis loop.In the first part of the paper Shape Memory Alloys are shortly described. Next mathematical model was formulated. In the paper the Preisach model was developed. Discrete form of the model was considered and implemented. After parameter identification model was implemented in LabView. Tests of the model were conducted and results were worked. Obtained characteristics of the SMA actuator are shown in the paper. At the end of the paper the conclusions were formulated.

scholarly journals Flexible Fingers Based on Shape Memory Alloy Actuated Modules

Machines ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 40 ◽  
Author(s):  
Daniela Maffiodo ◽  
Terenziano Raparelli
Keyword(s):  
Mathematical Model ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Basic Concept ◽  
Experimental Tests ◽  
Simple Mathematical Model ◽  
Joule Effect ◽  
Antagonistic Action ◽  
Preliminary Results

To meet the needs of present-day robotics, a family of gripping flexible fingers has been designed. Each of them consists of a number of independent and flexible modules that can be assembled in different configurations. Each module consists of a body with a flexible central rod and three longitudinally positioned shape memory alloy (SMA) wires. When heated by the Joule effect, one to two SMA wires shorten, allowing the module to bend. The return to undeformed conditions is achieved in calm air and is guaranteed by the elastic bias force exerted by the central rod. This article presents the basic concept of the module and a simple mathematical model for the design of the device. Experimental tests were carried out on three prototypes with bodies made of different materials. The results of these tests confirm the need to reduce the antagonistic action of the inactive SMA wires and led to the realization of a fourth prototype equipped with an additional SMA wire-driven locking/unlocking device for these wires. The preliminary results of this last prototype are encouraging.

Active Vibration Control of Epoxy Matrix Composite Beams with Embedded Shape Memory Alloy TiNi Fibers

2003 ◽  
Vol 17 (08n09) ◽  
pp. 1744-1749 ◽  
Author(s):  
T. Aoki ◽  
A. Shimamoto
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Vibration Control ◽  
Matrix Composite ◽  
Epoxy Matrix ◽  
Damping Ratio ◽  
Active Vibration Control ◽  
Composite Beams ◽  
Epoxy Matrix Composite ◽  
Active Vibration

In this paper, epoxy matrix composite beams with embedded TiNi (SMA: Shape Memory Alloy) fiber are applied to enhance the strength and fracture toughness of the machinery components. It is also well known that SMA shows the remarkable changes of stiffness and damping ratio between martensite at lower temperature and austenite at high temperature. A shape recovery force is associated with inverse phase transformation of SMA. The effects of heating with current and pre-strain in TiNi fiber of SMA on vibration characteristics are experimentally investigated. The active vibration control is achieved by controlling the current and pre-strain.

Design, Simulation and Testing of Shape Memory Alloy Actuator for Mixing Two Solutions in High-Pressure Optical Cell for Biophysical Studies

2006 ◽  
Author(s):  
Hongchun Xie ◽  
Jack Zhou ◽  
Parkson Chong
Keyword(s):  
High Pressure ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Nickel Titanium ◽  
Intensity Change ◽  
Optical Cell ◽  
Pull Out ◽  
Spring Force ◽  
Heat Response ◽  
Sma Spring

Window-type high-pressure optical cells (HPOC) such as the one designed by Paladini and Weber [Rev. Sci. Instrum. 52, (1981) p. 419] have provided biophysicists a powerful tool to understand the structure-function relationships of biological molecules. However, the conventional HPOC is only good for single solution testing and does not allow for quick mixing and stirring of additional components while the sample is under pressure. To mix two solutions under pressure, Zhou et al [Rev. Sci. Instrum. 69, (1998) p. 3958] developed a laser activated dual chamber HPOC. However, the expensive laser device and its unavailability in most laboratories make the application difficult. In a later study, Zhou et al. [Rev. Sci. Instrum. 71, (2000) p. 4249] introduced shape memory alloy (SMA) as an actuator to unplug a urethane stopper with a biasing spring for agitation. The drawback is that the biasing spring blocks the observing light beam and creates unwanted reflections. This research is to construct an actuator with concentric SMA spring and compressive biasing spring: an SMA helical tensile spring to pull out the stopper to let two solutions mix; and a helical compressive spring to bias and to agitate solutions, and to leave the lower half cuvette clear for optical observation. Due to the limited space in the cuvette, the alignment of two springs is critical for both motion and heat response to activate each spring separately. This paper discusses the design of SMA actuator, SMA spring testing and mixing testing by the SMA spring actuator. Since SMA (nickel-titanium) spring is not solderable and crimping method is limited due to the space, a conductive adhesive is used not only to fix the alignment between springs and cap, but also to conduct electric current. Spring force testing was done by INSTRON. Mixing testing used flourescein intensity change to trace the mixing process. The bio-compatibility of the nickel-titanium SMA with proteins and phospholipids has also been tested.

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