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1 – 10 of 12R. Jerome and N. Ganesan
A thermal analogy method for the static and dynamic analysis of an electrostrictive beam by incorporating the nonlinear characteristics of the electrostrictive materials is…
Abstract
A thermal analogy method for the static and dynamic analysis of an electrostrictive beam by incorporating the nonlinear characteristics of the electrostrictive materials is described in this paper. The analogy between thermo elastic finite element formulation and the electrostrictive material finite element formulation developed in this paper was explored. Based on this analogy, the voltage actuation of the electrostrictive beam can be simulated accurately using the conventional elastic finite element model with the thermal actuation. The finite element model includes the quadratic dependence of strain with electric field, valid at constant temperature and mechanical prestress, and excludes hysteresis.
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This paper gives a bibliographical review of the finite element methods (FEMs) applied to the analysis of ceramics and glass materials. The bibliography at the end of the paper…
Abstract
This paper gives a bibliographical review of the finite element methods (FEMs) applied to the analysis of ceramics and glass materials. The bibliography at the end of the paper contains references to papers, conference proceedings and theses/dissertations on the subject that were published between 1977‐1998. The following topics are included: ceramics – material and mechanical properties in general, ceramic coatings and joining problems, ceramic composites, ferrites, piezoceramics, ceramic tools and machining, material processing simulations, fracture mechanics and damage, applications of ceramic/composites in engineering; glass – material and mechanical properties in general, glass fiber composites, material processing simulations, fracture mechanics and damage, and applications of glasses in engineering.
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Piezoelectric actuators are well established for use in expensive optical equipment. Within the last decade, relatively inexpensive piezoelectric actuators have become established…
Abstract
Piezoelectric actuators are well established for use in expensive optical equipment. Within the last decade, relatively inexpensive piezoelectric actuators have become established technology in pneumatic switching and the first piezoelectrically driven impactive robot grippers are just starting to emerge. Although this article concentrates largely on the use of piezoelectric actuators for use in robot gripping systems, the potential for applications outside this field is immense.
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P. Glynne‐Jones and N.M. White
A range of self‐power technologies is reviewed. Self‐powered systems are defined as those that operate by harnessing ambient energy present within the environment of the system…
Abstract
A range of self‐power technologies is reviewed. Self‐powered systems are defined as those that operate by harnessing ambient energy present within the environment of the system. As MEMS and smart‐material technologies mature, embedded and remote systems become more attractive. Self‐power offers a potential for solving the difficult problem of supplying energy to these devices.
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Pin‐points three possibilities to do with micro‐actuators and micro assembly and discusses them in detail, using technical terms to enhance explanation. Concludes more will be…
Abstract
Pin‐points three possibilities to do with micro‐actuators and micro assembly and discusses them in detail, using technical terms to enhance explanation. Concludes more will be heard of these techniques in time to come.
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Eniko T. Enikov and Geon S. Seo
This paper describes the development and the numerical analysis of an electrochemical model for the analysis of a novel polymer/metal composite actuator. A general continuum model…
Abstract
This paper describes the development and the numerical analysis of an electrochemical model for the analysis of a novel polymer/metal composite actuator. A general continuum model describing the transport and deformation processes of these actuators is briefly presented, along with a detailed description of the simulation scheme used to predict deformation, current, and mass transport. The predictions of the model are compared with experimental data, indicating a significant role of water transport in the large‐scale deformation. Comparison of the simulations and experimental data showed good agreement confirming the central role of water transport in the deformation process. For the sake of completeness the fabrication process and testing apparatus are also described.
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Fikri Serdar Gokhan, Graham W. Griffiths and William E. Schiesser
The purpose of this paper is to present the method of lines (MOL) solution of the stimulated Brillouin scattering (SBS) equations (a system of three first-order hyperbolic partial…
Abstract
Purpose
The purpose of this paper is to present the method of lines (MOL) solution of the stimulated Brillouin scattering (SBS) equations (a system of three first-order hyperbolic partial differential equations (PDEs)), describing the three-wave interaction resulting from a coupling between light and acoustic waves. The system has complex numbers and boundary values.
Design/methodology/approach
System of three first-order hyperbolic PDEs are first transformed and then spatially discretized. Superbee flux limiter is proposed to offset numerical damping and dispersion, brought on by the low order approximation of spatial derivatives in the PDEs. In order to increase computational efficiency, the structured structure of the PDE Jacobian matrix is identified and a sparse integration algorithm option of the ordinary differential equation (ODE) solvers is used. The flux limiter based on higher order approximations eliminates numerical oscillation. Examples are presented, and the performance of the Matlab ODE solvers is evaluated by comparison.
Findings
This type of solution provides a rapid means of investigating SBS as a tool in fiber optic sensing.
Originality/value
To the best of the authors' knowledge, MOL solution is proposed for the first time for the modeling of three-wave interaction in a SBS-based fiber optic sensor.
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J.A. Palmer, B. Jokiel, C.D. Nordquist, B.A. Kast, C.J. Atwood, E. Grant, F.J. Livingston, F. Medina and R.B. Wicker
This paper presents a novel mesoscale RF (mRF) relay that integrates advanced high resolution stereolithography (SL) and micro wire electro discharge machining (μEDM…
Abstract
Purpose
This paper presents a novel mesoscale RF (mRF) relay that integrates advanced high resolution stereolithography (SL) and micro wire electro discharge machining (μEDM) technologies. Methods and infrastructure for reliable batch assembly of electromechanical actuators and structural parts less than 5 mm3 in volume are described. Switches made using these techniques are expected to have greater power handling capability relative to current micro RF relay products.
Design/methodology/approach
The conjecture is that the integration of SL and similar rapid additive manufacturing with other mesofabrication technologies can yield innovative miniature products with novel capabilities. A series of mRF prototypes consisting of a contact mechanism and actuator with return spring were fabricated assembled, inspected, and characterized for electromechanical performance. Characterization results led to specific conclusions regarding capabilities of the mRF product, and the integrated manufacturing technique.
Findings
The microassembly apparatus and epoxy‐based fastening system led to durable prototypes within 4 h (excluding a 16‐24 h cure cycle). Relay stroke ranged from 560 to 1,650 μm indicating a relative assembly accuracy of 90 percent. Prototypes demonstrated insertion loss of 1.3 dB at 100 MHz and isolation of better than 30 dB through 300 MHz.
Research limitations/implications
Results indicated that fully functional and robust mesoscale relays are possible using integrated manufacturing with SL. However, prototypes exhibited high contact resistance and lacked assembly precision in the context of contact mechanism stroke. Opportunities exist to reduce contact resistance and switching time.
Practical implications
The research provides a practical new product application for integrated mesoscale rapid manufacturing.
Originality/value
This work represents one of the first examples of a mesoscale relay rapidly manufactured with a combination of μEDM and SL components.
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Keywords
The use of fibre optic sensors is a relatively new development but the future applications are enormous
Ceramic materials and glasses have become important in modern industry as well as in the consumer environment. Heat resistant ceramics are used in the metal forming processes or…
Abstract
Purpose
Ceramic materials and glasses have become important in modern industry as well as in the consumer environment. Heat resistant ceramics are used in the metal forming processes or as welding and brazing fixtures, etc. Ceramic materials are frequently used in industries where a wear and chemical resistance are required criteria (seals, liners, grinding wheels, machining tools, etc.). Electrical, magnetic and optical properties of ceramic materials are important in electrical and electronic industries where these materials are used as sensors and actuators, integrated circuits, piezoelectric transducers, ultrasonic devices, microwave devices, magnetic tapes, and in other applications. A significant amount of literature is available on the finite element modelling (FEM) of ceramics and glass. This paper gives a listing of these published papers and is a continuation of the author's bibliography entitled “Finite element modelling of ceramics and glass” and published in Engineering Computations, Vol. 16, 1999, pp. 510‐71 for the period 1977‐1998.
Design/methodology/approach
The form of the paper is a bibliography. Listed references have been retrieved from the author's database, MAKEBASE. Also Compendex has been checked. The period is 1998‐2004.
Findings
Provides a listing of 1,432 references. The following topics are included: ceramics – material and mechanical properties in general, ceramic coatings and joining problems, ceramic composites, piezoceramics, ceramic tools and machining, material processing simulations, fracture mechanics and damage, applications of ceramic/composites in engineering; glass – material and mechanical properties in general, glass fiber composites, material processing simulations, fracture mechanics and damage, and applications of glasses in engineering.
Originality/value
This paper makes it easy for professionals working with the numerical methods with applications to ceramics and glasses to be up‐to‐date in an effective way.
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