Extended Bond Graph Reticulation of Piezoelectric Continua

1995 ◽  
Vol 117 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Fu-Shin Lee ◽  
Tess J. Moon ◽  
Glenn Y. Masada
Keyword(s):  
Piezoelectric Material ◽  
Electric Fields ◽  
Strain Energy ◽  
Electromechanical Coupling ◽  
Bond Graph ◽  
The Other ◽  
Discrete Models ◽  
Coupling Effects ◽  
Electromechanical Effects ◽  
Constitutive Properties

Extended Bond Graph (EBG) reticulations for general and linear piezoelectric continua are developed in this paper. The EBG formulation is especially advantageous for modeling the distributed coupled electromechanical effects of these materials and for combining this representation with other discrete models. The electromechanical coupling effects are represented by a multiport C-element for the general piezoelectric material. For linear constitutive properties, the coupling effects are represented by two multiport C-elements; one for the strain energy and the other for the capacitance storage, and a transformer that converts the power flows between the two energy domains. Details of the developments of the general formulation and of the specific models are provided. This work represents the first application of EBGs to electric fields.

scholarly journals Optimizing Piezoelectric Material Location and Size for Multiple-Mode Vibration Reduction of Turbomachinery Blades

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Christopher R. Kelley ◽  
Garrett K. Lopp ◽  
Jeffrey L. Kauffman
Keyword(s):  
Piezoelectric Material ◽  
Smart Materials ◽  
Strain Energy ◽  
Electromechanical Coupling ◽  
Vibration Reduction ◽  
Vibration Modes ◽  
Aerodynamic Efficiency ◽  
Sufficient Energy ◽  
Turbomachinery Blades ◽  
Mode Vibration

Abstract Modern turbomachinery blades have extremely low inherent damping, which can lead to high transient vibrations and failure through high-cycle fatigue. Smart materials enable vibration reduction while meeting strict blade requirements such as weight and aerodynamic efficiency. In particular, piezoelectric-based vibration reduction offers the potential to reduce vibration semi-actively while simultaneously harvesting sufficient energy to power the implementation. The placement and the size of the piezoelectric material is critical to the vibration reduction capabilities of the system. Furthermore, the implementation should target multiple vibration modes. This study develops a procedure to optimize electromechanical coupling across multiple vibration modes for a representative turbomachinery blade with surface-mounted piezoelectric patches. Experimental validation demonstrates good coupling across three targeted modes with a single piezoelectric patch. Placing the piezoelectric material in regions of high signed strain energy for all targeted modes enables vibration reduction across all of the targeted modes.

scholarly journals Contact interactions in complex fibrous metamaterials

2021 ◽  
Author(s):  
Mario Spagnuolo ◽  
Antonio M. Cazzani
Keyword(s):  
Strain Energy ◽  
Point Of View ◽  
The Other ◽  
Contact Interactions ◽  
Coupling Term ◽  
Dissipation Potential ◽  
Parallel Fibers ◽  
Mathematical Point

AbstractIn this work, an extension of the strain energy for fibrous metamaterials composed of two families of parallel fibers lying on parallel planes and joined by connective elements is proposed. The suggested extension concerns the possibility that the constituent fibers come into contact and eventually scroll one with respect to the other with consequent dissipation due to friction. The fibers interact with each other in at least three different ways: indirectly, through microstructural connections that could allow a relative sliding between the two families of fibers; directly, as the fibers of a family can touch each other and can scroll introducing dissipation. From a mathematical point of view, these effects are modeled first by introducing two placement fields for the two fiber families and adding a coupling term to the strain energy and secondly by adding two other terms that take into account the interdistance between the parallel fibers and the Rayleigh dissipation potential (to account for friction).

scholarly journals Pulsed Electric Fields to Improve the Use of Non-Saccharomyces Starters in Red Wines

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1472
Author(s):  
Cristian Vaquero ◽  
Iris Loira ◽  
Javier Raso ◽  
Ignacio Álvarez ◽  
Carlota Delso ◽  
...  
Keyword(s):  
Electric Fields ◽  
Pulsed Electric Fields ◽  
The Other ◽  
Red Wines ◽  
Torulaspora Delbrueckii ◽  
Wild Yeast ◽  
Wild Yeasts ◽  
Natural Foods ◽  
Saccharomyces Yeasts ◽  
Lachancea Thermotolerans

New nonthermal technologies, including pulsed electric fields (PEF), open a new way to generate more natural foods while respecting their organoleptic qualities. PEF can reduce wild yeasts to improve the implantation of other yeasts and generate more desired metabolites. Two PEF treatments were applied; one with an intensity of 5 kV/cm was applied continuously to the must for further colour extraction, and a second treatment only to the must (without skins) after a 24-hour maceration of 17.5 kV/cm intensity, reducing its wild yeast load by up to 2 log CFU/mL, thus comparing the implantation and fermentation of inoculated non-Saccharomyces yeasts. In general, those treated with PEF preserved more total esters and formed more anthocyanins, including vitisin A, due to better implantation of the inoculated yeasts. It should be noted that the yeast Lachancea thermotolerans that had received PEF treatment produced four-fold more lactic acid (3.62 ± 0.84 g/L) than the control of the same yeast, and Hanseniaspora vineae with PEF produced almost three-fold more 2-phenylethyl acetate than the rest. On the other hand, 3-ethoxy-1-propanol was not observed at the end of the fermentation with a Torulaspora delbrueckii (Td) control but in the Td PEF, it was observed (3.17 ± 0.58 mg/L).

A Multi-Cylinder HCCI Engine Model for Control

2004 ◽  
Author(s):  
Jason S. Souder ◽  
Parag Mehresh ◽  
J. Karl Hedrick ◽  
Robert W. Dibble
Keyword(s):  
Design Process ◽  
Control Design ◽  
The Other ◽  
Variable Valve Timing ◽  
Valve Timing ◽  
Coupling Effects ◽  
Hcci Engine ◽  
Engine Model ◽  
Hcci Engines ◽  
Variable Valve

Homogeneous charge compression ignition (HCCI) engines are a promising engine technology due to their low emissions and high efficiencies. Controlling the combustion timing is one of the significant challenges to practical HCCI engine implementations. In a spark-ignited engine, the combustion timing is controlled by the spark timing. In a Diesel engine, the timing of the direct fuel injection controls the combustion timing. HCCI engines lack such direct in-cylinder mechanisms. Many actuation methods for affecting the combustion timing have been proposed. These include intake air heating, variable valve timing, variable compression ratios, and exhaust throttling. On a multi-cylinder engine, the combustion timing may have to be adjusted on each cylinder independently. However, the cylinders are coupled through the intake and exhaust manifolds. For some of the proposed actuation methods, affecting the combustion timing on one cylinder influences the combustion timing of the other cylinders. In order to implement one of these actuation methods on a multi-cylinder engine, the engine controller must account for the cylinder-to-cylinder coupling effects. A multi-cylinder HCCI engine model for use in the control design process is presented. The model is comprehensive enough to capture the cylinder-to-cylinder coupling effects, yet simple enough for the rapid simulations required by the control design process. Although the model could be used for controller synthesis, the model is most useful as a starting point for generating a reduced-order model, or as a plant model for evaluating potential controllers. Specifically, the model includes the dynamics for affecting the combustion timing through exhaust throttling. The model is readily applicable to many of the other actuation methods, such as variable valve timing. Experimental results validating the model are also presented.

Electromechanical coupling effects for data storage and synaptic devices

Nano Energy ◽  
2020 ◽  
Vol 77 ◽  
pp. 105156
Author(s):  
Liangchao Guo ◽  
Su-Ting Han ◽  
Ye Zhou
Keyword(s):  
Data Storage ◽  
Electromechanical Coupling ◽  
Coupling Effects

Correlations of substituent effects on proton and fluorine chemical shifts with inverse ionization potentials

1967 ◽  
Vol 45 (24) ◽  
pp. 3143-3151 ◽  
Author(s):  
T. Schaefer ◽  
F. Hruska ◽  
H. M. Hutton
Keyword(s):  
Electric Fields ◽  
Chemical Shifts ◽  
Substituent Effects ◽  
Group Iv ◽  
The Other ◽  
Ionization Potentials ◽  
Time Dependent ◽  
Practical Application ◽  
Methyl Proton ◽  
Proton Chemical Shifts

The fluorine and proton chemical shifts in some geminally disubstituted vinylidene fluorides and ethylenes are discussed. For these compounds, at least, there are difficulties with an interpretation based on intramolecular time-dependent electric fields. On the other hand, the shifts correlate with the inverse ionization potentials of the substituents, indicating a paramagnetic effect arising from the second term in Ramsey's expression. It is suggested that the effect operates via the bonds and not across space. Methyl proton shifts in a series of substituted methyl compounds of group IV, V, and VI elements show similar correlations. A practical application of the correlation to spectral analysis problems is given.

Electromechanical coupling and design considerations in single-layer MoS2 suspended-channel transistors and resonators

Nanoscale ◽  
2015 ◽  
Vol 7 (47) ◽  
pp. 19921-19929 ◽  
Author(s):  
Rui Yang ◽  
Arnob Islam ◽  
Philip X.-L. Feng
Keyword(s):  
Field Effect ◽  
Electromechanical Coupling ◽  
Field Effect Transistors ◽  
Single Layer ◽  
Systematic Investigation ◽  
Coupling Effects ◽  
Design Considerations

We describe systematic investigation of electromechanical coupling effects in suspended single-layer MoS2, as suspended-channel field-effect transistors and vibrating-channel nanoelectromechanical resonators.

Application of an Equivalent Circuit Model for Ionic Polymer-Metal Composite (IPMC) Bending Actuator Loaded With Multiwalled Carbon Nanotube (M-CNT)

2006 ◽  
Vol 309-311 ◽  
pp. 593-596 ◽  
Author(s):  
Deuk Yong Lee ◽  
Kwang Jin Kim ◽  
Seok Heo ◽  
Myung Hyun Lee ◽  
Bae Yeon Kim
Keyword(s):  
Elastic Modulus ◽  
Carbon Nanotube ◽  
Equivalent Circuit ◽  
Electric Fields ◽  
Electromechanical Coupling ◽  
Equivalent Circuit Model ◽  
Metal Composite ◽  
Multiwalled Carbon ◽  
Equivalent Circuit Analysis ◽  
Bending Actuator

Biomimetic actuators that can produce soft-actuation but large force generation capability are of interest. NafionTM, an effective ionomeric material from DuPont, has been shown to produce large deformation under low electric fields (<10V/mm). In this effort, multi-walled carbon nanotube (M-CNT)/NafionTM nanocomposites were prepared by casting in order to investigate the effect of M-CNT loading in the range of 0 to 7 wt% on electromechanical properties of the MCNT/ NafionTM nanocomposites. The measured elastic modulus and actuation force of the MCNT/ NafionTM nanocomposites are drastically different, showing larger elastic modulus and improved electromechanical coupling, from the one without M-CNT. In this work, we attempted to incorporate an equivalent circuit analysis to address the effect of capacitance and resistance of such M-CNT/NafionTM nanocomposites that would differ from conventional IPMCs.

scholarly journals ELECTRIC FORCE LINES OF THE DOUBLE REISSNER–NORDSTROM EXACT SOLUTION

2008 ◽  
Vol 17 (08) ◽  
pp. 1159-1177 ◽  
Author(s):  
ARMANDO PAOLINO ◽  
MARCO PIZZI
Keyword(s):  
Exact Solution ◽  
Black Hole ◽  
Electric Fields ◽  
Maxwell Equation ◽  
Naked Singularity ◽  
Extreme Case ◽  
The Other ◽  
Electric Force ◽  
Coordinate Systems ◽  
Equal Sign

Recently Alekseev and Belinski have presented a new exact solution to the Einstein–Maxwell equation which describes two Reissner–Nordstrom (RN) sources in reciprocal equilibrium (no struts or strings); one source is a naked singularity, the other is a black hole: this is the only possible configuration for two separable objects, apart from the well-known extreme case (mi = ei). In the present paper, after a brief summary of this solution, we study in some detail the coordinate systems used and the main features of the gravitational and electric fields. In particular, we graph the plots of the electric force lines in three qualitatively different situations: equal-sign charges, opposite charges and the case of a naked singularity near a neutral black hole.

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