Timoshenko Elastic and Electroelastic Beam Models Incorporating the Local Mass Displacement Effect

2021 ◽  
pp. 303-322
Author(s):  
Olha Hrytsyna
Keyword(s):  
Displacement Effect ◽  
Local Mass ◽  
Mass Displacement ◽  
Local Mass Displacement

Electromechanical fields in a hollow piezoelectric cylinder under non-uniform load: flexoelectric effect

2021 ◽  
pp. 108128652110207
Author(s):  
Olha Hrytsyna
Keyword(s):  
Analytical Solutions ◽  
Point Group ◽  
The Body ◽  
Small Scale ◽  
Gradient Theory ◽  
Local Mass ◽  
Wide Range ◽  
Mass Displacement ◽  
Local Mass Displacement ◽  
Local Gradient

The relations of a local gradient non-ferromagnetic electroelastic continuum are used to solve the problem of an axisymmetrical loaded hollow cylinder. Analytical solutions are obtained for tetragonal piezoelectric materials of point group 4 mm for two cases of external loads applied to the body surfaces. Namely, the hollow pressurized cylinder and a cylinder subjected to an electrical voltage V across its thickness are considered. The derived solutions demonstrate that the non-uniform electric load causes a mechanical deformation of piezoelectric body, and vice versa, the inhomogeneous radial pressure of the cylinder induces its polarization. Such a result is obtained due to coupling between the electromechanical fields and a local mass displacement being considered. In the local gradient theory, the local mass displacement is associated with the changes to a material’s microstructure. The classical theory does not consider the effect of material microstructure on the behavior of solid bodies and is incapable of explaining the mentioned phenomena. It is also shown that the local gradient theory describes the size-dependent properties of piezoelectric nanocylinders. Analytical solutions to the formulated boundary-value problems can be used in conjunction with experimental data to estimate some higher-order material constants of the local gradient piezoelectricity. The obtained results may be useful for a wide range of appliances that utilize small-scale piezoelectric elements as constituting blocks.

Local gradient Bernoulli–Euler beam model for dielectrics: effect of local mass displacement on coupled fields

2020 ◽  
pp. 108128652096337
Author(s):  
Olha Hrytsyna
Keyword(s):  
Strain Gradient Theory ◽  
Beam Deflection ◽  
Small Scale ◽  
Gradient Theory ◽  
Beam Model ◽  
Euler Beam ◽  
Local Mass ◽  
Mass Displacement ◽  
Local Mass Displacement ◽  
Local Gradient

The size-dependent behaviour of a Bernoulli–Euler nanobeam based on the local gradient theory of dielectrics is investigated. By using the variational principle, the linear stationary governing equations of the local gradient beam model and corresponding boundary conditions are derived. In this set of equations the coupling between the strain, the electric field and the local mass displacement is taken into account. Within the presented theory, the process of local mass displacement is associated with the non-diffusive and non-convective mass flux related to the changes in the material microstructure. The solution to the static problem of an elastic cantilever piezoelectric beam subjected to end-point loading is used to investigate the effect of the local mass displacement on the coupled electromechanical fields. The obtained solution is compared to the corresponding ones provided by the classical theory and strain gradient theory. It is shown that the beam deflection predicted by the local gradient theory is smaller than that by the classical Bernoulli–Euler beam theory when the beam thickness is comparable to the material length-scale parameter. The obtained results also indicate that the piezoelectricity has a significant influence on the electromechanical response in a dielectric nanobeam. The presented mathematical model of the dielectric beam may be useful for the study of electromechanical coupling in small-scale piezoelectric structures.

Quantitation in thin Sections Within the Electron Microscope

1976 ◽  
Vol 34 ◽  
pp. 336-337
Author(s):  
J. Edie
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Electron Scattering ◽  
Volume Density ◽  
Thin Sections ◽  
Faraday Cage ◽  
Local Mass ◽  
Physical Measurements ◽  
Mass Volume ◽  
Varying Mass

In TEM image formation, the observed contrast variations within thin sections result from differential electron scattering within microregions of varying mass thickness. It is possible to utilize these electron scattering properties to obtain objective information regarding various specimen parameters (1, 2, 3).A pragmatic, empirical approach is described which enables a microscopist to perform physical measurements of thickness of thin sections and estimates of local mass, volume, density and, possibly, molecular configurations within thin sections directly in the microscope. A Faraday cage monitors the transmitted electron beam and permits measurements of electron beam intensities.

Influence of gait pattern on the body's centre of mass displacement in children with cerebral palsy

2004 ◽  
Vol 46 (10) ◽  
Author(s):  
Firas Massaad ◽  
Frédéric Dierick ◽  
Adélaïde van den Hecke ◽  
Christine Detrembleur
Keyword(s):  
Cerebral Palsy ◽  
Gait Pattern ◽  
Centre Of Mass ◽  
Children With Cerebral Palsy ◽  
Mass Displacement

ANALISIS BERITA POLITIK PADA SURAT KABAR HARIAN (SKH) KEDAULATAN RAKYAT TENTANG PEMBERANTASAN KORUPSI DI ERA PEMERINTAHAN JOKOWI-JK

2019 ◽  
Vol 2 (2) ◽  
pp. 223-250
Author(s):  
Ririn Risnawati
Keyword(s):  
Social Context ◽  
Mass Media ◽  
Critical Discourse Analysis ◽  
Text Structure ◽  
The Political ◽  
Daily Newspaper ◽  
Political News ◽  
Local Mass ◽  
News Analysis ◽  
The Mass Media

This study examines the Political News Analysis of the Sovereignty of the People's Sovereignty on Eradicating Corruption as the Independence of the Mass Media in Proclaiming the Performance of the Jokowi-JK Government which focuses on 1 year of its administration (20 October 2014 October 20 2015). This research is based on two things, namely: first, how is the analysis of the political news regarding Corruption Eradication in the local mass media (Kedaulatan Rakyat) in reporting on the performance of the Jokowi-JK government; second, how the independence of the local mass media in reporting on the performance of the Jokowi-JK government in the area of ??corruption eradication. Media independence is seen from the method of Qualitative Approach with Critical Paradigm namely Critical Discourse Analysis; using Teun A. van Dijk's Model Analysis of text production involving aspects of cognition and social context.  The production of text in the political news regarding the Eradication of Corruption in Judging the Performance of the Jokowi-JK Government presented by the Kedaulatan Rakyat SKH is a strong text structure. The Kedaulatan Rakyat Daily Newspaper is able to provide detailed Semantic Structure and more coherent relationships between words / sentences. In addition, the Kedaulatan Rakyat Daily Newspaper minimizes graphics and metaphor as rhetorical elements so as to be able to present more real and factual news. starting from text, social cognition and social context. The news on SKH Kedaulatan Rakyat is able to present the factual news objectivity in accordance with the truth and relevance. Not only that, the objectivity of the news about justice is able to be fulfilled by the People's Sovereignty SKH by presenting balanced news and explaining it more neutral without the support of the mass media. Keywords: Political News, Independence, Mass Media, Eradication of Corruption

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