scholarly journals Solution of the problem of impact elastoplastic deformation of a thin layer of mechanoluminophor using the methods of the dislocation microdynamic theory of plasticity

2019 ◽  
Vol 221 ◽  
pp. 01047
Author(s):  
Konstantin Tatmyshevskiy
Keyword(s):  
Thin Layer ◽  
Optical Radiation ◽  
Strong Electric Field ◽  
Radiation Energy ◽  
Direct Conversion ◽  
Sensing Element ◽  
Optical Signals ◽  
Flexible Polymer ◽  
Basic Equations ◽  
The Mathematical Model

The paper presents the results of numerical simulation of the output optical signals of mechanoluminescent shock sensors. Such sensors operate on the principle of direct conversion of mechanical impact energy into optical radiation energy. The sensing element of such a sensor is a thin layer of phosphor enclosed between two transparent flexible polymer films. The mathematical model of the sensor is based on the process of excitation of the glow centers (activator atoms) in a strong electric field of a moving dislocation. The stress-strain state of the film sensing element under quasi-static uniaxial loading under the action of a single pressure pulse is considered. The analysis of constitutive equations for elasto-plastic deformations and the basic equations of the dynamic theory of dislocations. To calculate the deformation of the sensing element, a microscopic model of an isotropic elastic-plastic medium with hardening is used, according to which the plastic deformation is considered as a result of the movement and multiplication of dislocations, and the hardening is as a result of their partial locking due to the increased density.

scholarly journals A New Approach of Soft Joint Based on a Cable-Driven Parallel Mechanism for Robotic Applications

Mathematics ◽  
2021 ◽  
Vol 9 (13) ◽  
pp. 1468
Author(s):  
Luis Nagua ◽  
Carlos Relaño ◽  
Concepción A. Monje ◽  
Carlos Balaguer
Keyword(s):  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Kinematic Model ◽  
Experimental Tests ◽  
Humanoid Robots ◽  
Inverse Kinematic ◽  
Element Analysis ◽  
New Approach ◽  
Flexible Polymer ◽  
The Mathematical Model

A soft joint has been designed and modeled to perform as a robotic joint with 2 Degrees of Freedom (DOF) (inclination and orientation). The joint actuation is based on a Cable-Driven Parallel Mechanism (CDPM). To study its performance in more detail, a test platform has been developed using components that can be manufactured in a 3D printer using a flexible polymer. The mathematical model of the kinematics of the soft joint is developed, which includes a blocking mechanism and the morphology workspace. The model is validated using Finite Element Analysis (FEA) (CAD software). Experimental tests are performed to validate the inverse kinematic model and to show the potential use of the prototype in robotic platforms such as manipulators and humanoid robots.

scholarly journals Mathematical analogies in physics. Thin-layer wave theory

2014 ◽  
Vol 57 (1) ◽  
Author(s):  
José M. Carcione ◽  
Vivian Grünhut ◽  
Ana Osella
Keyword(s):  
Quantum Mechanics ◽  
Thin Layer ◽  
Quantum Physics ◽  
Constitutive Relations ◽  
Normal Incidence ◽  
Wave Theory ◽  
Transverse Magnetic ◽  
Momentum Conservation ◽  
Tunnel Effect ◽  
Basic Equations

<p>Field theory applies to elastodynamics, electromagnetism, quantum mechanics, gravitation and other similar fields of physics, where the basic equations describing the phenomenon are based on constitutive relations and balance equations. For instance, in elastodynamics, these are the stress-strain relations and the equations of momentum conservation (Euler-Newton law). In these cases, the same mathematical theory can be used, by establishing appropriate mathematical equivalences (or analogies) between material properties and field variables. For instance, the wave equation and the related mathematical developments can be used to describe anelastic and electromagnetic wave propagation, and are extensively used in quantum mechanics. In this work, we obtain the mathematical analogy for the reflection/refraction (transmission) problem of a thin layer embedded between dissimilar media, considering the presence of anisotropy and attenuation/viscosity in the viscoelastic case, conductivity in the electromagnetic case and a potential barrier in quantum physics (the tunnel effect). The analogy is mainly illustrated with geophysical examples of propagation of S (shear), P (compressional), TM (transverse-magnetic) and TE (transverse-electric) waves. The tunnel effect is obtained as a special case of viscoelastic waves at normal incidence.</p>

scholarly journals Numerical simulation of changes in the electric properties of biological tissues under local heating by laser radiation

2021 ◽  
Vol 2090 (1) ◽  
pp. 012049
Author(s):  
N V Kovalenko ◽  
A V Smirnov ◽  
O A Ryabushkin
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Laser Radiation ◽  
Optical Radiation ◽  
Local Heating ◽  
Biological Tissues ◽  
Electric Properties ◽  
Reliable Tool ◽  
The Mathematical Model

Abstract The mathematical model that describes the local heating of biological tissues by optical radiation is introduced. Changes of the electric properties of biological tissues in such process can be used as a reliable tool for analyzing heating and damage degrees of tissues.

scholarly journals Application features of micro-pixel avalanche photodetectors in the laser Doppler anemometers

2021 ◽  
Vol 2057 (1) ◽  
pp. 012088
Author(s):  
V V Rakhmanov ◽  
S V Dvoynishnikov ◽  
V G Meledin ◽  
V A Pavlov ◽  
D O Semenov
Keyword(s):  
Optical Radiation ◽  
Avalanche Photodiodes ◽  
Laser Doppler Anemometer ◽  
Optical Receiver ◽  
Laser Doppler ◽  
Silicon Photomultiplier ◽  
Optical Signals ◽  
Avalanche Photodetectors ◽  
The Cost ◽  
To Receive

Abstract The optical receiver is an essential part of any laser Doppler anemometer. Traditionally, vacuum photomultiplier tubes are used for reliable reception of weak optical radiation. However, this type of photodetector has its own drawbacks, which lead to a design complication and an increase in the cost of LDA. In this work, the characteristics of silicon micropixel avalanche photodiodes are investigated and the operation of a silicon photomultiplier as a photodetector in an LDA is tested when measuring the velocity on test benches. The possibility of using Si-PMT to receive optical signals of the laser Doppler anemometer is shown.

scholarly journals Comparative Analysis of Optical Signals Emitted by Corona on a Laboratory Model of Transmission Lines Made of Various Materials

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Sławomir Krzewiński ◽  
Paweł Frącz ◽  
Ireneusz Urbaniec ◽  
Tomasz Turba
Keyword(s):  
Transmission Lines ◽  
Optical Radiation ◽  
Power Transmission ◽  
Experimental Tests ◽  
Laboratory Model ◽  
Pure Aluminium ◽  
Power Transmission Lines ◽  
Optical Signals ◽  
Three Phase ◽  
System Operating

The paper presents results of comparative analyses of optical signals generated by corona discharges occurring in the vicinity and on the surface of power transmission lines made of five different materials under laboratory conditions. Three aluminium-based materials were chosen: pure aluminium, aluminium with added magnesium, and aluminium with added silicon, and for comparison purposes also, steel-based lines were considered: copper-coated steel and steel with added chromium and nickel. A three-phase triangular arrangement system operating under maximal voltage equal to 110 kV was applied for experimental tests. The optical radiation was registered using a spectrophotometer. During research works, also the influence of corona generation voltage and distance between power lines was investigated. Based on the achieved results, it was stated that the highest corona intensity was found for aluminium-based lines, for both pure aluminium and aluminium with added magnesium and silicon. The lowest corona intensity was observed for chromium- and nickel-alloyed (stainless) steel.

Contact of the edges of the interphase cut on the arc of the circle between the isotropic plate and the closed elastic rib

2021 ◽  
Vol 103 (3) ◽  
pp. 88-97
Author(s):  
Аndrii Siaskyi ◽  
Volodymyr Siaskyi ◽  
Natalia Shevtsova
Keyword(s):  
Stress State ◽  
Isotropic Plate ◽  
Singular Integral Equations ◽  
Contact Forces ◽  
Deformation Tensor ◽  
Elastic Rod ◽  
Smooth Contact ◽  
Basic Equations ◽  
The Mathematical Model ◽  
Angle Of Rotation

In the conditions of the general flat stress state created by uniformly distributed effects of tension (compression) at infinity, the mixed contact problem for an infinite isotropic plate with a circular hole, which contour reinforced by a closed elastic rib in the presence of a symmetrical interfacial section at the boundary of their connection and the edges of cut in the process of deformation is smoothly contacted, is considered. The components of the deformation tensor (unit elongation, the angle of rotation of the normal and the curvature) at the point of the contour of the hole of the plate are represented by integral dependences on the contact forces. By modeling the reinforcement of a closed elastic rod of a stable rectangular cross of large curvature and using the basic equations of linear theory of curvilinear rods the mathematical model of problems is constructed in the form of systems of three singular integral equations with Hilbert cores to find contact forces between plates and rib. To determine the initial parameters of a closed static indeterminate rod, the conditions of unambiguous displacement and angles of rotation at the point of its axis and the equilibrium conditions are used. The approximate solution of the problem is constructed by the method of mechanical quadrature and collocations, which investigated the influence on the stress state of the plate and the reinforcing rib and on the size of the area of smooth contact of stiffness factor of rib.

Modeling of optical radiation energy distribution in plant tissue

2009 ◽  
Vol 107 (6) ◽  
pp. 903-908 ◽  
Author(s):  
V. P. Zakharov ◽  
I. A. Bratchenko ◽  
A. R. Sindyaeva ◽  
E. V. Timchenko
Keyword(s):  
Energy Distribution ◽  
Plant Tissue ◽  
Optical Radiation ◽  
Radiation Energy
Sign in / Sign up

Export Citation Format

Share Document