Frictional Hysteresis Model for Stick–Slip Behavior of Magnetorheological Elastomer Under Various Magnetic Field Strengths

2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Jinwoo Lim ◽  
Kwang-Hee Lee ◽  
Chul-Hee Lee
Keyword(s):  
Magnetic Field ◽  
Mathematical Models ◽  
Simple Structure ◽  
Magnetorheological Elastomer ◽  
Lugre Model ◽  
Stick Slip ◽  
Friction Dampers ◽  
Parameter Variations ◽  
System Output ◽  
Frictional Hysteresis

In recent studies, many mathematical models have been introduced to describe the shear deformation characteristics of a magnetorheological elastomer (MRE). Owing to its beneficial elastomeric characteristics, an MRE can be adopted in novel controllable devices such as friction dampers and brakes. In this study, mathematical models are introduced to identify the frictional behavior of an MRE under different magnetic field conditions. Specifically, the improved LuGre (I-LuGre) model and the strain-stiffening model are compared using a system identification method. To identify the model that best describes the stick/slip behavior of an MRE, a harmonic frictional force was exerted on its surface with magnetic fields of varying strength. The I-LuGre model showed a precise correlation with the experimental results, and the strain-stiffening model was shown to have a simple structure for describing the frictional phenomenon. The system output error of the I-LuGre model remained within smaller errors than that of the strain-stiffening model. The parameter variations of each model that can be utilized to construct a control strategy are provided herein.

scholarly journals Design, Analysis, and Experiment on a Novel Stick-Slip Piezoelectric Actuator with a Lever Mechanism

Micromachines ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 863 ◽  
Author(s):  
Weiqing Huang ◽  
Mengxin Sun
Keyword(s):  
Piezoelectric Actuator ◽  
Simple Structure ◽  
Fast Response ◽  
Displacement Sensor ◽  
Design Parameters ◽  
The Finite Element Method ◽  
Stick Slip ◽  
Lever Mechanism ◽  
Series Of Experiments ◽  
Stator Design

A piezoelectric actuator using a lever mechanism is designed, fabricated, and tested with the aim of accomplishing long-travel precision linear driving based on the stick-slip principle. The proposed actuator mainly consists of a stator, an adjustment mechanism, a preload mechanism, a base, and a linear guide. The stator design, comprising a piezoelectric stack and a lever mechanism with a long hinge used to increase the displacement of the driving foot, is described. A simplified model of the stator is created. Its design parameters are determined by an analytical model and confirmed using the finite element method. In a series of experiments, a laser displacement sensor is employed to measure the displacement responses of the actuator under the application of different driving signals. The experiment results demonstrate that the velocity of the actuator rises from 0.05 mm/s to 1.8 mm/s with the frequency increasing from 30 Hz to 150 Hz and the voltage increasing from 30 V to 150 V. It is shown that the minimum step distance of the actuator is 0.875 μm. The proposed actuator features large stroke, a simple structure, fast response, and high resolution.

scholarly journals A Magneto-Active Elastomer Crawler with Peristaltic and Caterpillar Locomotion Patterns

Actuators ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 74
Author(s):  
Tsam Lung You ◽  
Hemma Philamore ◽  
Fumitoshi Matsuno
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
External Magnetic Field ◽  
Mathematical Models ◽  
Confined Spaces ◽  
Low Mass ◽  
Structural Simplicity

In this work we present a soft crawler fabricated using a magneto-active elastomer. The crawler is controlled by an external magnetic field to produce two locomotion patterns: peristaltic and caterpillar crawling. Due to its structural simplicity, low mass, wirelessly controlled actuation and compliant body the design of this crawler has the potential to address the key challenges faced by existing crawling robots. Experimental data were gathered to evaluate the performance of the crawler locomotion in a pipe. The results validated the mathematical models proposed to estimate the distance traveled by the crawler. The crawler shows potential for use in exploration of confined spaces.

Modelling and experimental characterisation of a compressional adaptive magnetorheological elastomer isolator

2021 ◽  
pp. 107754632110253
Author(s):  
Emiliano Rustighi ◽  
Diego F Ledezma-Ramirez ◽  
Pablo E Tapia-Gonzalez ◽  
Neil Ferguson ◽  
Azrul Zakaria
Keyword(s):  
Magnetic Field ◽  
Silicone Rubber ◽  
Magnetic Interaction ◽  
Iron Particle ◽  
Material Model ◽  
Rubber Matrix ◽  
Magnetorheological Elastomer ◽  
Volume Percentage ◽  
Shock Absorbers ◽  
Percent Concentration

This article proposes a simple physical-based model to describe and predict the performance of axially compressed magnetorheological elastomer cylinders used as vibration and shock absorbers. The model describes the magnetorheological elastomer macroscopic stiffness changes because of an externally applied magnetic field from a microscopic composite cell of silicone rubber and carbonyl iron particle. Despite neglecting the material hyperelasticity, anisotropy and adjacent magnetic interaction, the model describes effectively the effect of the magnetic field on the macroscopic modulus of elasticity. The changes in the mechanical properties with the induced magnetic field are measured on samples of different particle concentration based on volume percentage, that is, 10 and 30 percent concentration of iron particles in a silicone rubber matrix. The manufacturing process of the samples is detailed, as well as the experimental validation of the effective stiffness change under a magnetic field in terms of transmissibility and mobility testing. However, the prediction seems to be limited by the linear elastic material model. Predictions and measurements are compared, showing that the model is capable of predicting the tunability of the dynamic/shock absorber and that the proposed devices have a possible application in the reduction of mechanical vibrations.

Feasibility study of an adaptive mount system based on magnetorheological elastomer using real-time hybrid simulation

2018 ◽  
Vol 30 (5) ◽  
pp. 701-707 ◽  
Author(s):  
Seung-Hyun Eem ◽  
Jeong-Hoi Koo ◽  
Hyung-Jo Jung
Keyword(s):  
Magnetic Field ◽  
Control System ◽  
Real Time ◽  
Control Algorithm ◽  
Vibration Reduction ◽  
Hybrid Simulation ◽  
Shaking Table ◽  
Magnetorheological Elastomer ◽  
Experimental Part ◽  
Hybrid Simulations

This article investigates an adaptive mount system based on magnetorheological elastomer in reducing the vibration of an equipment on the isolation table. Incorporating MR elastomers, whose elastic modulus or stiffness can be adjusted depending on the applied magnetic field, the proposed mount system strives to alleviate the limitations of existing passive-type mount systems. The primary goal of this study is to evaluate the vibration reduction performance of the proposed MR elastomer mount using the hybrid simulation technique. For real-time hybrid simulations, the MR elastomer mount and the control system are used as an experimental part, which is installed on the shaking table, and an equipment on the table is used as a numerical part. A suitable control algorithm is designed for the real-time hybrid simulations to avoid the responses of the equipment’s natural frequency by tracking the frequencies of the responses. After performing a series of real-time hybrid simulation on the adaptive mount system and the passive-type mount system under sinusoidal excitations, this study compares the effectiveness of the adaptive mount system over its passive counterpart. The results show that the proposed adaptive elastomer mount system outperforms the passive-type mount system in reducing the responses of the equipment for the excitations considered in this study.

Edgewise Bending Vibration Analysis of a Rotating Sandwich Beam with Magnetorheological Elastomer Core

2018 ◽  
Vol 18 (11) ◽  
pp. 1850134 ◽  
Author(s):  
S. Bornassi ◽  
H. M. Navazi ◽  
H. Haddadpour
Keyword(s):  
Magnetic Field ◽  
Layer Thickness ◽  
Rectangular Cross Section ◽  
Ritz Method ◽  
Sandwich Beam ◽  
Beam Theory ◽  
Core Layer ◽  
Magnetorheological Elastomer ◽  
Bending Vibration ◽  
Elastic Layers

The vibration of a rotating sandwich beam with magnetorheological elastomer (MRE) as a core between two elastic layers is theoretically analyzed in this paper. This study is focused on the bending vibration along the edgewise direction of a sandwich beam of rectangular cross-section, which, to the best of our knowledge, has not been addressed yet. The classical Euler–Bernoulli beam theory is used to model the dynamic behavior of the elastic layers. In the modeling, the effect of the MRE layer is considered by incorporating its shear strains and the inertia due to shear deformation and bending motion. The governing equations of motion of the rotating sandwich beam are derived by using the Ritz method and the Lagrange’s equations. The effects of the applied magnetic field, core layer thickness, rotational speed, setting angle and hub radius on the natural frequencies and the corresponding loss factors are investigated parametrically. The results show the significant effect of the magnetic field intensity and the MRE layer thickness on the modal characteristics of the MRE sandwich beam.

Attenuation and rheological analysis of magnetic field-induced responsiveness for the magnetorheological elastomer-based composite

2021 ◽  
Author(s):  
Longsheng Chen ◽  
qian Lv ◽  
yao Gong ◽  
Lili Zou
Keyword(s):  
Magnetic Field ◽  
Storage Period ◽  
Morphological Properties ◽  
Future Application ◽  
Magnetorheological Elastomer ◽  
Rheological Analysis ◽  
Cyclic Shear ◽  
Mr Effect ◽  
The Impact ◽  
Storage Temperatures

Abstract A novel self-supporting multi-layer magnetorheological elastomer-based (MRE-based) composite with large magnetic field-induced responsiveness has been designed and fabricated. We characterized its morphological properties, evaluated the impact of fabrication conditions on its field-induced responsiveness, investigated attenuation of its field-induced responsiveness under different storage temperatures along with time and analyzed this mechanism from the perspective of rheology. The results showed that the MRE-based composite had homogeneous dispersing of the magnetic fillers and a clear interface between different layers. The field-induced responsiveness of the MRE-based composite could be affected by the fabrication conditions, and it attenuated at different rates when subjected to different storage temperatures along with time; its attenuation period lasted a few days under room temperature while over one month under low temperature (4℃). The rheological analysis results indicated a long-term cross-linking process over the storage period along with the attenuation of field-induced responsiveness, which might lead to increasing elasticity (indicated by the loss factor tan δ) and rigidity (indicated by the storage modulus G') of the MRE-based composite along with the storage period. What's more, emerging feature of Payne effect could be found on MRE-based composite during cyclic shear, which indicated decline of the mechanical properties due to strain-induced inherent friction. On the other hand, the iron fillers in MRE layer could enhance the shear modulus and lead to MR effect (up to 187%) for the whole composite, which benefits to the magnetic field-induced responsiveness, due to the relative strengthen of the MRE layer against the assist layer. This work presents a better understanding on the attenuation of the field-induced responsiveness, which is important for the future application of the MRE-based composite.

Studies of Magnetically Active Silicone Elastomers on a Vibrostend

2021 ◽  
Vol 1037 ◽  
pp. 141-147
Author(s):  
Andrey Minaev ◽  
Juri Korovkin ◽  
Hammat Valiev ◽  
G.V. Stepanov ◽  
Dmitry Yu. Borin
Keyword(s):  
Magnetic Field ◽  
Field Effect ◽  
Dynamic Properties ◽  
Experimental Studies ◽  
Magnetic Field Effect ◽  
Magnetorheological Elastomer ◽  
Silicone Elastomers ◽  
Damping Coefficients ◽  
Deformation Properties ◽  
The Magnetic Field

Experimental studies magnetorheological elastomer specimens dynamic properties under the magnetic fields action on the vibrostend are carried out. Amplitude-frequency characteristics have been obtained. The magnetic field effect on the silicone magnetoreactive elastomers deformation properties and damping coefficients experimentally is established.

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