An Electric Node Concept for Solid-Shell Elements for Laminate Composite Piezoelectric Structures

2005 ◽  
Vol 72 (1) ◽  
pp. 35-43 ◽  
Author(s):  
Lin-Quan Yao ◽  
Li Lu
Keyword(s):  
Exact Solution ◽  
Finite Element ◽  
Electric Fields ◽  
Electric Potential ◽  
Potential Distribution ◽  
Smart Structure ◽  
Finite Element Models ◽  
Solid Shell ◽  
Shell Elements ◽  
Electric Potential Distribution

The eight-node solid-shell finite element models have been developed for the analysis of laminated composite plate/shell structures embedded with piezoelectric actuators and sensors. To resolve the locking problems of the solid-shell elements in laminated materials and improve accuracy, the assumed natural strain method and hybrid stress method are employed. Introduction of the concept of the electric nodes can effectively eliminate the burden of constraining the equality of the electric potential for the nodes lying on the same electrode. Furthermore, the nonlinear electric potential distribution in piezoelectric layer is described by introducing internal electric potential. The developed finite element models, especially electric potential node model, are simpler over other models but can still obtain same accuracy as exact solution described. Several examples are studied and compared with exact solution and other predicted results to illustrate the accuracy of the present model, and efficacy and effect caused by nonlinear electric potential distribution on frequency and electric fields in smart structure modeling.

Seismoelectric numerical modeling on a grid

Geophysics ◽  
2006 ◽  
Vol 71 (6) ◽  
pp. N57-N65 ◽  
Author(s):  
Seth S. Haines ◽  
Steven R. Pride
Keyword(s):  
Electric Fields ◽  
Electric Potential ◽  
Potential Distribution ◽  
Seismic Waves ◽  
Fresnel Zone ◽  
Near Field ◽  
Fluid Pressure ◽  
Heterogeneous Porous Media ◽  
Time Step ◽  
Electric Potential Distribution

Our finite-difference algorithm provides a new method for simulating how seismic waves in arbitrarily heterogeneous porous media generate electric fields through an electrokinetic mechanism called seismoelectric coupling. As the first step in our simulations, we calculate relative pore-fluid/grain-matrix displacement by using existing poroelastic theory. We then calculate the electric current resulting from the grain/fluid displacement by using seismoelectric coupling theory. This electrofiltration current acts as a source term in Poisson’s equation, which then allows us to calculate the electric potential distribution. We can safely neglect induction effects in our simulations because the model area is within the electrostatic near field for the depth of investigation (tens to hundreds of meters) and the frequency ranges ([Formula: see text] to [Formula: see text]) of interest for shallow seismoelectric surveys.We can independently calculate the electric-potential distribution for each time step in the poroelastic simulation without loss of accuracy because electro-osmotic feedback (fluid flow that is perturbed by generated electric fields) is at least [Formula: see text] times smaller than flow that is driven by fluid-pressure gradients and matrix acceleration, and is therefore negligible. Our simulations demonstrate that, distinct from seismic reflections, the seismoelectric interface response from a thin layer (at least as thin as one-twentieth of the seismic wavelength) is considerably stronger than the response from a single interface. We find that the interface response amplitude decreases as the lateral extent of a layer decreases below the width of the first Fresnel zone. We conclude, on the basis of our modeling results and of field results published elsewhere, that downhole and/or crosswell survey geometries and time-lapse applications are particularly well suited to the seismoelectric method.

scholarly journals Quantitative Observation of Electric Potential Distribution of Brittle Polyelectrolyte Hydrogels Using Microelectrode Technique

2016 ◽  
Vol 49 (8) ◽  
pp. 3100-3108 ◽  
Author(s):  
Honglei Guo ◽  
Takayuki Kurokawa ◽  
Masakazu Takahata ◽  
Wei Hong ◽  
Yoshinori Katsuyama ◽  
...  
Keyword(s):  
Electric Potential ◽  
Potential Distribution ◽  
Electric Potential Distribution ◽  
Microelectrode Technique

scholarly journals Observation of Electric Potential Distribution in Model Capacitor Sample Using Electron Holography

2012 ◽  
Vol 53 (4) ◽  
pp. 696-699 ◽  
Author(s):  
Ryuichi Kuramae ◽  
Hiroyuki Ono ◽  
Yoshinori Fujikawa ◽  
Yasukazu Murakami ◽  
Daisuke Shindo
Keyword(s):  
Electric Potential ◽  
Potential Distribution ◽  
Electron Holography ◽  
Electric Potential Distribution

scholarly journals Validation of the stream function method used for reconstruction of experimental ionospheric convection patterns

2000 ◽  
Vol 18 (4) ◽  
pp. 454-460
Author(s):  
P.L. Israelevich ◽  
V. O. Papitashvili ◽  
A. I. Ershkovich
Keyword(s):  
Boundary Value Problem ◽  
Boundary Conditions ◽  
Stream Function ◽  
Electric Fields ◽  
Electric Potential ◽  
Potential Distribution ◽  
Function Method ◽  
Polar Cap ◽  
Ionospheric Convection ◽  
Convection Patterns

Abstract. In this study we test a stream function method suggested by Israelevich and Ershkovich for instantaneous reconstruction of global, high-latitude ionospheric convection patterns from a limited set of experimental observations, namely, from the electric field or ion drift velocity vector measurements taken along two polar satellite orbits only. These two satellite passes subdivide the polar cap into several adjacent areas. Measured electric fields or ion drifts can be considered as boundary conditions (together with the zero electric potential condition at the low-latitude boundary) for those areas, and the entire ionospheric convection pattern can be reconstructed as a solution of the boundary value problem for the stream function without any preliminary information on ionospheric conductivities. In order to validate the stream function method, we utilized the IZMIRAN electrodynamic model (IZMEM) recently calibrated by the DMSP ionospheric electrostatic potential observations. For the sake of simplicity, we took the modeled electric fields along the noon-midnight and dawn-dusk meridians as the boundary conditions. Then, the solution(s) of the boundary value problem (i.e., a reconstructed potential distribution over the entire polar region) is compared with the original IZMEM/DMSP electric potential distribution(s), as well as with the various cross cuts of the polar cap. It is found that reconstructed convection patterns are in good agreement with the original modelled patterns in both the northern and southern polar caps. The analysis is carried out for the winter and summer conditions, as well as for a number of configurations of the interplanetary magnetic field.Key words: Ionosphere (electric fields and currents; plasma convection; modelling and forecasting)

scholarly journals Single point incremental forming simulation with adaptive remeshing technique using solid-shell elements

2016 ◽  
Vol 33 (5) ◽  
pp. 1388-1421 ◽  
Author(s):  
José I.V. Sena ◽  
Cedric Lequesne ◽  
L Duchene ◽  
Anne-Marie Habraken ◽  
Robertt A.F. Valente ◽  
...  
Keyword(s):  
Finite Element ◽  
Incremental Forming ◽  
Single Point ◽  
Nonlinear Material ◽  
Single Point Incremental Forming ◽  
Solid Shell ◽  
Contact Conditions ◽  
Adaptive Remeshing ◽  
Content Type ◽  
Shell Elements

Purpose – Numerical simulation of the single point incremental forming (SPIF) processes can be very demanding and time consuming due to the constantly changing contact conditions between the tool and the sheet surface, as well as the nonlinear material behaviour combined with non-monotonic strain paths. The purpose of this paper is to propose an adaptive remeshing technique implemented in the in-house implicit finite element code LAGAMINE, to reduce the simulation time. This remeshing technique automatically refines only a portion of the sheet mesh in vicinity of the tool, therefore following the tool motion. As a result, refined meshes are avoided and consequently the total CPU time can be drastically reduced. Design/methodology/approach – SPIF is a dieless manufacturing process in which a sheet is deformed by using a tool with a spherical tip. This dieless feature makes the process appropriate for rapid-prototyping and allows for an innovative possibility to reduce overall costs for small batches, since the process can be performed in a rapid and economic way without expensive tooling. As a consequence, research interest related to SPIF process has been growing over the last years. Findings – In this work, the proposed automatic refinement technique is applied within a reduced enhanced solid-shell framework to further improve numerical efficiency. In this sense, the use of a hexahedral finite element allows the possibility to use general 3D constitutive laws. Additionally, a direct consideration of thickness variations, double-sided contact conditions and evaluation of all components of the stress field are available with solid-shell and not with shell elements. Additionally, validations by means of benchmarks are carried out, with comparisons against experimental results. Originality/value – It is worth noting that no previous work has been carried out using remeshing strategies combined with hexahedral elements in order to improve the computational efficiency resorting to an implicit scheme, which makes this work innovative. Finally, it has been shown that it is possible to perform accurate and efficient finite element simulations of SPIF process, resorting to implicit analysis and continuum elements. This is definitively a step-forward on the state-of-art in this field.

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