Dynamic characterization of a laminated composite magnetorheological fluid sandwich plate
TL;DR: In this article, the authors investigated the effect of a magnetic field on the variation of the natural frequencies and loss factors of a laminated composite magnetorheological (MR) fluid sandwich plate under various boundary conditions.
Abstract: This study investigates the dynamic properties of a laminated composite magnetorheological (MR) fluid sandwich plate. The governing differential equations of motion of a sandwich plate embedding a MR fluid layer as the core layer and laminated composite plates as the face layers are presented in a finite element formulation. The validity of the developed finite element formulation is demonstrated by comparing the results in terms of the natural frequencies derived from the present finite element formulation with those in the available literature. Various parametric studies are also performed to investigate the effect of a magnetic field on the variation of the natural frequencies and loss factors of the MR fluid composite sandwich plate under various boundary conditions. Furthermore, the effect of the thickness of the MR fluid layer and the ply orientation of the composite face layers on the variation of the natural frequencies and loss factors are studied. The free vibration mode shapes under various boundary conditions of a MR fluid laminated composite sandwich plate are also presented. The forced vibration response of a MR fluid composite plate is investigated to study the dynamic response of the sandwich plate under harmonic force excitations in various magnetic fields. The study suggests that the natural frequency increases with increasing magnetic field, irrespective of the boundary conditions. The reduction in peak deflection at each mode under a harmonic excitation force with variation of the applied magnetic field shows the effectiveness of the MR fluid layer in reducing the vibration amplitude of the composite sandwich plate.
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TL;DR: In this article, the dynamic buckling analysis of sandwich plates with magnetorheological (MR) fluid core and piezoelectric nanocomposite facesheets is presented.
51 citations
TL;DR: In this paper, the vibration responses of a partially treated composite magnetorheological (MR) fluid sandwich plate have been investigated and the governing differential equations of motion have been analyzed.
Abstract: In this study, the vibration responses of a partially treated laminated composite magnetorheological (MR) fluid sandwich plate have been investigated. The governing differential equations of motion...
44 citations
Cites background from "Dynamic characterization of a lamin..."
...A partially treated MR fluid sandwich plate structure (Figure 1(d)) can be modeled on the basis of a fully treated MR fluid sandwich plate (Figure 1 (b)) (Manoharan et al. 2014)....
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...The dynamic properties of a laminated composite MR fluid sandwich plate were investigated recently by Manoharan et al. (2014)....
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TL;DR: In this article, a three-layered sandwich beam with an adaptive magneto-rheological fluid (MRF) core layer is investigated, and the authors derived the instability bounds based on the classical beam theory for the face layers, magnetic field dependent complex modulus approach for viscoelastic material model and the linear first-order piston theory for aerodynamic pressure.
35 citations
TL;DR: In this article, the optimal locations of magnetorheological elastomer (MRE) segments in partially treated tapered composite MRE sandwich plates to maximize the natural frequencies and the loss factors were investigated.
34 citations
TL;DR: In this article, the authors developed a sandwich structure formed by embedding magnetorheological elastomers (MRE) between constrained layers of carbon fibre-reinforced plastic (CFRP) laminates.
Abstract: The aim of this work was the development of sandwich structures formed by embedding magnetorheological elastomers (MRE) between constrained layers of carbon fibre–reinforced plastic (CFRP) laminates. The MREs were obtained by mechanical stirring of a reactive mixture of substrates with carbonyl-iron particles, followed by orienting the particles into chains under an external magnetic field. Samples with particle volume fractions of 11.5% and 33% were examined. The CFRP/MRE sandwich structures were obtained by compressing MREs samples between two CFRP laminates composed. The used A.S.SET resin was in powder form and the curing process was carried out during pressing with MRE. The microstructure of the manufactured sandwich beams was inspected using SEM. Moreover, the rheological and damping properties of the examined materials with and without a magnetic field were experimentally investigated. In addition, the free vibration responses of the adaptive three-layered MR beams were studied at different fixed magnetic field levels. The free vibration tests revealed that an applied non-homogeneous magnetic field causes a shift in natural frequency values and a reduction in the vibration amplitudes of the CFRP/MRE adaptive beams. The reduction in vibration amplitude was attributed mainly to the stiffening effect of the MRE core and only a minor contribution was made by the enhanced damping capacity, which was evidenced by the variation in damping ratio values.
34 citations
References
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TL;DR: In this paper, a three-layered symmetric sandwich beam with magnetorheological elastomer (MRE) embedded viscoelastic core and conductive skins subjected to a periodic axial load have been carried out under various boundary conditions.
146 citations
TL;DR: In this article, a semi-analytical method has been presented to evaluate the natural frequencies as well as displacement and stress eigenvectors for simply supported, cross-ply laminated and sandwich plates by using higher order mixed theory.
132 citations
TL;DR: In this article, two optimal displacement control strategies for semi-active control of seismic response of frame structures using magnetorheological dampers or electrorheological (ER) dampers are proposed.
Abstract: Semi-active control of buildings and structures for earthquake hazard mitigation represents a relatively new research area. Two optimal displacement control strategies for semi-active control of seismic response of frame structures using magnetorheological (MR) dampers or electrorheological (ER) dampers are proposed in this study. The efficacy of these displacement control strategies is compared with the optimal force control strategy. The stiffness of brace system supporting the smart damper is also taken into consideration. An extensive parameter study is carried out to find the optimal parameters of MR or ER fluids, by which the maximum reduction of seismic response may be achieved, and to assess the effects of earthquake intensity and brace stiffness on damper performance. The work on example buildings showed that the installation of the smart dampers with proper parameters and proper control strategy could significantly reduce seismic responses of structures, and the performance of the smart damper is better than that of the common brace or the passive devices. The optimal parameters of the damper and the proper control strategy could be identified through a parameter study. Copyright © 2000 John Wiley & Sons, Ltd.
127 citations
TL;DR: In this paper, the viscoelastic properties of magnetorheological (MR) fluids were investigated using a strain-controlled rheometer with plate-plate configuration, and the results showed that both storage modulus and loss modulus G´ and loss factor increased with the increment of the strain amplitude.
Abstract: Mechanical properties of magnetorheological (MR) fluids are classified into pre-yield and post-yield regions according to whether the shear stress is below or above the yield stress. MR fluids within the pre-yield region exhibit viscoelastic properties; and these properties are important for understanding MR suspensions, especially for vibration damping applications. MR suspensions composed of reduced iron powders dispersed in silicone oil are utilized to study the viscoelastic properties with the help of a strain-controlled rheometer with plate-plate configuration. Two types of experiments, i.e. strain-amplitude sweep mode and frequency-sweep mode, were carried out to investigate the viscoelastic properties of MR fluids: (a) strain-amplitude sweep mode, the strain amplitude was swept from 0.0001 to 0.001 at a fixed driving frequency of 10 Hz. (b) Frequency-sweep mode, the driving frequency was swept from 1 Hz to 100 Hz at a constant strain amplitude of 0.001. The results show that both storage modulus G´ and loss modulus G´´ decrease with the increment of the strain amplitude, however, the loss factor increases with the increment of the strain amplitude. On the other hand, both the storage modulus and loss modulus increase with the increment of frequency, which is different from the loss factor. Moreover, the effects of magnetic field and volume fraction on the viscoelastic properties are also investigated. The higher the magnetic field, the higher the storage modulus and loss modulus, and the lower the loss factor. The higher the volume fraction, the higher the storage modulus and the loss factor.
123 citations
TL;DR: In this paper, the authors investigated the properties of a multi-layered beam with MR fluid as a sandwich layer between the two layers of the continuous elastic structure and formulated the governing equations of a multilayer MR beam in the finite element form and using the Ritz method.
Abstract: Magnetorheological (MR) materials exhibit rapid variations in their rheological properties when subjected to varying magnetic field and thus offer superior potential for applications in smart structures requiring high bandwidth. MR sandwich structures can apply distributed control force to yield variations in stiffness and damping properties of the structure in response to the intensity of the applied magnetic field and could thus provide vibration suppression over a broad range of external excitation frequencies. This study investigates the properties of a multi-layered beam with MR fluid as a sandwich layer between the two layers of the continuous elastic structure. The governing equations of a multi-layer MR beam are formulated in the finite element form and using the Ritz method. A free oscillation experiment is performed to estimate the relationship between the magnetic field and the complex shear modulus of the MR materials in the pre-yield regime. The validity of the finite element and Ritz formulations developed is examined by comparing the results from the two models with those from the experimental investigation. Various parametric studies have been performed in terms of variations of the natural frequencies and loss factor as functions of the applied magnetic field and thickness of the MR fluid layer for various boundary conditions. The forced vibration responses of the MR sandwich beam are also evaluated under harmonic force excitation. The results illustrate that the natural frequencies could be increased by increasing the magnetic field while the magnitudes of the peak deflections could be considerably decreased, which demonstrates the vibration suppression capability of the MR sandwich beam.
122 citations