Improved Model of Middle Layer Used for Design of Piezoelectric Bimorph Actuator

2014 ◽  
Vol 1004-1005 ◽  
pp. 393-398
Author(s):  
Yu Hua Zhou ◽  
Chang Sheng Zhou ◽  
Xiong Chen
Keyword(s):  
Mathematical Model ◽  
Composite Material ◽  
Physical Model ◽  
Performance Prediction ◽  
Adhesive Layer ◽  
Middle Layer ◽  
Electrical Load ◽  
Piezoelectric Bimorph ◽  
Actual Structure ◽  
Improved Model

In this study, the disadvantage that adhesive layer of piezoelectric bimorph actuator was ignored when model of actuator was developed by predecessors is indicated, according to the actual structure of actuator. Based on the thickness of adhesive layer and substrate, the improved model of adhesive layer that substrate and adhesive layer are combined as one layer called mid layer is proposed. Mathematical model of mid layer can be obtained with theory of composite material, which is then used to develop the model of actuator under electrical load. Another model of actuator is developed as a reference in the same way except with model of adhesive layer used by predecessors, and experiment is also presented later. Performance predicted by these two models of actuator and result measured in the experiment are compared, which comes to a conclusion that model of actuator developed with the improved model of adhesive layer conform to the physical model and is more precise in performance prediction.

scholarly journals Modelling Fabric’s Optical Behaviors

2008 ◽  
Vol 575-578 ◽  
pp. 1266-1271 ◽  
Author(s):  
Hong Ying Yang ◽  
Su Kang Zhu ◽  
Ke Jing Li ◽  
Ning Pan
Keyword(s):  
Mathematical Model ◽  
Optical Properties ◽  
Physical Model ◽  
Structural Parameters ◽  
Incident Light ◽  
Optical Parameters ◽  
Light Component ◽  
Light Components ◽  
Improved Model ◽  
The Mathematical Model

In this paper, existing models of fabric’s optical behaviors are classified and estimated briefly. Then, basing on the optical theories, this paper abstracts the commonness of fabric’s optical behaviors and put forward an improved model of them, which includes a physical model and its corresponding mathematical model. The physical model describes the light falling on fabrics splits into six components, which compose another four components. The ten light components divided by the incident light yields ten light component parameters, which are functions of the wavelength. The mathematical model connects the ten light component parameters and gives formulas to calculate them. Thus, the light component parameters are connected with the basic optical parameters and structural parameters of fabric. This improved model provides a fundamental and theoretical guide for studying fabric’s optical properties systematically, which has been proved to be effective in solving some problems related fabric optical properties.

EXPERIMENTAL STUDIES OF CAR PROPERTIES ON A PHYSICAL MODEL

2019 ◽  
pp. 10-16
Author(s):  
Oleksii Timkov ◽  
Dmytro Yashchenko ◽  
Volodymyr Bosenko
Keyword(s):  
Mathematical Model ◽  
Remote Control ◽  
Physical Model ◽  
Model Experiment ◽  
Experimental Studies ◽  
Electrical Energy ◽  
Short Term ◽  
Motor Current ◽  
Memory Card ◽  
The Mathematical Model

The article deals with the development of a physical model of a car equipped with measuring, recording and remote control equipment for experimental study of car properties. A detailed description of the design of the physical model and of the electronic modules used is given, links to application libraries and the code of the first part of the program for remote control of the model are given. Atmega microcontroller on the Arduino Uno platform was used to manage the model and register the parameters. When moving the car on the memory card saved such parameters as speed, voltage on the motor, current on the motor, the angle of the steered wheel, acceleration along three coordinate axes are recorded. Use of more powerful microcontrollers will allow to expand the list of the registered parameters of movement of the car. It is possible to measure the forces acting on the elements of the car and other parameters. In the future, it is planned to develop a mathematical model of motion of the car and check its adequacy in conducting experimental studies on maneuverability on the physical model. In addition, it is possible to conduct studies of stability and consumption of electrical energy. The physical model allows to quickly change geometric dimensions and mass parameters. In the study of highway trains, this approach will allow to investigate the various layout schemes of highway trains in the short term. It is possible to make two-axle road trains and saddle towed trains, three-way hitched trains of different layout. The results obtained will allow us to improve not only the mathematical model, but also the experimental physical model, and move on to further study the properties of hybrid road trains with an active trailer link. This approach allows to reduce material and time costs when researching the properties of cars and road trains. Keywords: car, physical model, experiment, road trains, sensor, remote control, maneuverability, stability.

The Estimation of Thermal Conductivity for Alumina-Epoxy Composite Material with High Filling Volume Fraction

2014 ◽  
Vol 918 ◽  
pp. 21-26
Author(s):  
Chen Kang Huang ◽  
Yun Ching Leong
Keyword(s):  
Thermal Conductivity ◽  
Composite Material ◽  
Composite Materials ◽  
Physical Model ◽  
Electron Scattering ◽  
Volume Fraction ◽  
Epoxy Composite ◽  
The Matrix ◽  
Transport Theorem ◽  
Good Agreement

In this study, the transport theorem of phonons and electrons is utilized to create a model to predict the thermal conductivity of composite materials. By observing or assuming the dopant displacement in the matrix, a physical model between dopant and matrix can be built, and the composite material can be divided into several regions. In each region, the phonon or electron scattering caused by boundaries, impurities, or U-processes was taken into account to calculate the thermal conductivity. The model is then used to predict the composite thermal conductivity for several composite materials. It shows a pretty good agreement with previous studies in literatures. Based on the model, some discussions about dopant size and volume fraction are also made.

Effect of Freestream Radial Velocity Component on Hydrodynamic Analysis of Propellers

1983 ◽  
Vol 27 (02) ◽  
pp. 131-134
Author(s):  
Terry Brockett
Keyword(s):  
Mathematical Model ◽  
Radial Velocity ◽  
Performance Prediction ◽  
Velocity Component ◽  
Additional Term ◽  
Radial Component ◽  
Radial Velocity Component ◽  
Hydrodynamic Analysis ◽  
The Mathematical Model ◽  
Wake Fields

For wake fields with circumferential averages that include a small radial component, an additional termarises in the mathematical model used for design or performance prediction of propellers that has been previously overlooked. This term arises from the boundary condition that the blade is impenetrable and is a function of only geometry and the inflow radial velocity component. This simple additional term is shown to be important for the example considered, leading to a variable change in camber and a pitch reduction.

scholarly journals Modeling and Experiment of a V-Shaped Piezoelectric Energy Harvester

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Yue Zhao ◽  
Yi Qin ◽  
Lei Guo ◽  
Baoping Tang
Keyword(s):  
Energy Harvesting ◽  
Frequency Band ◽  
Electromechanical Coupling ◽  
Energy Harvester ◽  
Structural Parameters ◽  
Ambient Vibration ◽  
Piezoelectric Bimorph ◽  
Actual Structure ◽  
Piezoelectric Energy ◽  
Operation Frequency

Vibration-based energy harvesting technology is the most promising method to solve the problems of self-powered wireless sensor nodes, but most of the vibration-based energy harvesters have a rather narrow operation bandwidth and the operation frequency band is not convenient to adjust when the ambient frequency changes. Since the ambient vibration may be broadband and changeable, a novel V-shaped vibration energy harvester based on the conventional piezoelectric bimorph cantilevered structure is proposed, which successfully improves the energy harvesting efficiency and provides a way to adjust the operation frequency band of the energy harvester conveniently. The electromechanical coupling equations are established by using Euler-Bernoulli equation and piezoelectric equation, and then the coupled circuit equation is derived based on the series connected piezoelectric cantilevers and Kirchhoff's laws. With the above equations, the output performances of V-shaped structure under different structural parameters and load resistances are simulated and discussed. Finally, by changing the angle θ between two piezoelectric bimorph beams and the load resistance, various comprehensive experiments are carried out to test the performance of this V-shaped energy harvester under the same excitation. The experimental results show that the V-shaped energy harvester can not only improve the frequency response characteristic and the output performance of the electrical energy, but also conveniently tune the operation bandwidth; thus it has great application potential in actual structure health monitoring under variable working condition.

Development of a Mathematical Model for Performance Prediction of Planing Catamaran in Calm Water

2019 ◽  
Vol 161 (A2) ◽  
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Performance Prediction ◽  
Data Evaluation ◽  
Empirical Equations ◽  
Calm Water ◽  
Semi Empirical ◽  
The Mathematical Model ◽  
Comparison With Experimental Data

In this paper, an attempt has been made to predict the performance of a planing catamaran using a mathematical model. Catamarans subjected to a common hydrodynamic lift, have an extra lift between the two asymmetric half bodies. In order to develop a mathematical model for performance prediction of planing catamarans, existing formulas for hydrodynamic lift calculation must be modified. Existing empirical and semi-empirical equations in the literature have been implemented and compared against available experimental data. Evaluation of lift in comparison with experimental data has been documented. Parameters influencing the interaction between demi-hulls and separation effects have been analyzed. The mathematical model for planing catamarans has been developed based on Savitsky’s method and results have been compared against experimental data. Finally, the effects of variation in hull geometry such as deadrise angle and distance between two half bodies on equilibrium trim angle, resistance and wetted surface have been examined.

scholarly journals Economic Analysis of Solar Refrigeration and Desalination System

2019 ◽  
Vol 118 ◽  
pp. 02021
Author(s):  
Xiaoman Zhang ◽  
Qin Shen ◽  
Shijun Zhu
Keyword(s):  
Mathematical Model ◽  
Economic Analysis ◽  
Physical Model ◽  
Energy Supply ◽  
Recovery Period ◽  
Heat Consumption ◽  
Refrigeration System ◽  
Generation System ◽  
Refrigeration Capacity ◽  
Solar Refrigeration

The physical model and mathematical model of solar refrigeration and desalination co-generation system were established. The performance and economy of the system were analyzed by changing the three variables of refrigeration capacity, seawater desalination effects number and three different cities. The results show that increasing refrigeration capacity is conducive to improving freshwater production and increasing freshwater efficiency, but more auxiliary heat consumption is needed, the comprehensive effect is to shorten the recovery period. Increasing desalination efficiency is conducive to increasing freshwater production and freshwater efficiency, and the auxiliary heat consumption remains unchanged. The comprehensive effect is to shorten the recovery period. Solar energy is the main energy needed in the co-generation system of the three cities, and Shenzhen has the largest proportion of energy supply, which reaches 67.8%. Compared with the solar refrigeration system, the recovery period of the co-generation system can bu shortened by 18.1%.

Comparison of Electroplated Ni and PVD Ni Coating Layers after Soft Soldering Process

2019 ◽  
Vol 809 ◽  
pp. 367-371
Author(s):  
Jessica Richter ◽  
Benjamin Schellscheidt ◽  
Anna Steenmann ◽  
Thomas Licht
Keyword(s):  
Composite Material ◽  
Phase Formation ◽  
Intermetallic Phase ◽  
Adhesive Layer ◽  
Performance Comparison ◽  
Growth Patterns ◽  
Process Time ◽  
Power Electronic ◽  
Columnar Growth ◽  
Soldering Process

This work is part of a publicly funded project called ReffiMaL (resource efficient material solutions for power electronics), which aims to substitute electroplated Nickel (Ni) as contact material in power electronic modules. The baseplates of these power electronic modules are based on the metal matrix composite material AlSiC, which needs to be coated to become solderable. Today, it is state-of-the-art technology to coat the baseplate with electroplated Ni to form an adhesive layer to the system solder. In this paper we present a performance comparison of physical vapor deposited (PVD) Ni and electroplated Ni. The main advantage of PVD Ni is a significant reduction of layer thickness compared to the electroplating process. Second advantage of PVD Ni is the limitation of the deposition to areas that get soldered, in contrast to a non-selective electroplated coating. When deposited by PVD at room temperature, Ni exhibits columnar growth patterns, whereas electroplated Ni tends to form a laminar layer. The columnar growth leads to an increase in interface area affecting phase formation behavior. To compare both adhesion layers, we investigate the phase formation after soldering with a Sn based soft solder-copper composite material. The baseplates are reflow-soldered at different temperatures and process times. Temperature varied between 270°C and 400°C. The corresponding process time ranged from 10 to 40 minutes. We inspect the samples optically to determine the phase formation. Intermetallic phase (IMP) composition is evaluated using energy dispersive X-ray analysis (EDX). ReffiMaL is funded by the German Federal Ministry of Education and Research (BMBF).

scholarly journals Bifurcation phenomena and statistical regularities in dynamics of forced impacting oscillator

2019 ◽  
Vol 98 (3) ◽  
pp. 1795-1806 ◽  
Author(s):  
Sergii Skurativskyi ◽  
Grzegorz Kudra ◽  
Krzysztof Witkowski ◽  
Jan Awrejcewicz
Keyword(s):  
Differential Equation ◽  
Mathematical Model ◽  
Physical Model ◽  
Dry Friction ◽  
Stepper Motor ◽  
Nonlinear Phenomenon ◽  
Hertz Contact ◽  
Bifurcation Phenomena ◽  
Statistical Regularities ◽  
The Mathematical Model

Abstract The paper is devoted to the study of harmonically forced impacting oscillator. The physical model for oscillator is a cart on a guide connected to the support with springs and excited by the stepper motor. The support also is provided with limiter of motion. The mathematical model for this system is defined with the second-order piecewise smooth differential equation. Model’s nonlinearity is connected with the incorporation of dry friction and generalized Hertz contact law. Analyzing the classical Poincare sections and inter-impact sequences obtained experimentally and numerically, the bifurcations and statistical properties of periodic, multi-periodic, and chaotic regimes were examined. The development of impact-adding regime as a new nonlinear phenomenon when the forcing frequency varies was observed.

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