Using Nonlinear Contact Mechanics in Process of Tool Edge Movement on Deformable Body to Analysis of Cutting and Sliding Burnishing Processes

2014 ◽  
Vol 474 ◽  
pp. 339-344 ◽  
Author(s):  
Jaroslaw Chodor ◽  
Leon Kukielka
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Surface Layer ◽  
Numerical Methods ◽  
Contact Problem ◽  
Deformable Body ◽  
Comprehensive Analysis ◽  
Tool Edge ◽  
Nonlinear Contact ◽  
Performance Conditions

Properties of the surface layer after cutting or sliding burnishing depend mainly on type of process and its performance conditions. For its comprehensive analysis is necessary to develop an adequate mathematical model and numerical methods of solving it. A common feature of both processes is moving the tool edge on elastic/visco-plastic workpiece. However, these processes are different i.e. the chip formation or chipless forming, therefore, different properties of surface layer depend mainly on: the geometry of the tool edge and its workpiece relative and depth of process. Therefore, this article is about the application of an incremental modelling and numerical solution of the contact problem between movable rigid and elastic/visco-plastic bodies developed in [ to the numerical simulation of physical process of moving a rigid tool on the workpiece.

Numerical Simulation of Forming Force in Lateral Bend Forming

2010 ◽  
Vol 152-153 ◽  
pp. 1120-1124
Author(s):  
Chuan Min Zhang ◽  
Wen Zhi Fu ◽  
Fei Liu ◽  
Ming Zhe Li ◽  
Qi Qian Liu
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Finite Element Method ◽  
Finite Element ◽  
Contact Problem ◽  
Yield Limit ◽  
Main Principle ◽  
Bend Section ◽  
Forming Force ◽  
Angle Steel

The lateral bend forming is a new flexible forming method which bend section steel into parts with all kinds of curvature. The main principle and advantages of lateral bend forming is introduced. Mathematical model of lateral bend forming is established based on finite element method. Contact problem is treated. The law of forming force versus process parameters is analyzed by numerical simulation technology. The results shown as follows: the forming force is increased with the increment of the pressing quantity; the higher yield limit of material is, the bigger forming force is; the forming force of angle steel is bigger than sheet metal without changing other parameters.

scholarly journals A Quasistatic Contact Problem for Viscoelastic Materials with Slip-Dependent Friction and Time Delay

2012 ◽  
Vol 2012 ◽  
pp. 1-22
Author(s):  
Si-sheng Yao ◽  
Nan-jing Huang
Keyword(s):  
Mathematical Model ◽  
Variational Inequality ◽  
Time Delay ◽  
Contact Problem ◽  
Deformable Body ◽  
Constitutive Law ◽  
Time Dependent ◽  
Delay Term ◽  
Inequality System ◽  
Differential Variational Inequality

A mathematical model which describes an explicit time-dependent quasistatic frictional contact problem between a deformable body and a foundation is introduced and studied, in which the contact is bilateral, the friction is modeled with Tresca’s friction law with the friction bound depending on the total slip, and the behavior of the material is described with a viscoelastic constitutive law with time delay. The variational formulation of the mathematical model is given as a quasistatic integro-differential variational inequality system. Based on arguments of the time-dependent variational inequality and Banach's fixed point theorem, an existence and uniqueness of the solution for the quasistatic integro-differential variational inequality system is proved under some suitable conditions. Furthermore, the behavior of the solution with respect to perturbations of time-delay term is considered and a convergence result is also given.

Applications of Numerical Simulation of Solar Cooker Type Box With Multi-Step Inner Reflector

Solar Energy ◽  
2003 ◽  
Author(s):  
H. Terre´s-Pen˜a ◽  
P. Quinto-Diez
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Numerical Methods ◽  
Thermal Conversion ◽  
Numerical Results ◽  
Kutta Method ◽  
Runge Kutta Method ◽  
Energetic Analysis ◽  
The Mathematical Model ◽  
Solar Rays

It is shown a mathematical model of a solar box cooker with multi-step inner reflector and the numerical results for two applications has been analyzed. These applications are 1. Numerical simulation of operation of solar box cooker with multi-step inner reflector in Tanta, Egypt and 2. Numerical simulation of solar box cooker with multi-step inner reflector for 10 hours of operation. In the case 1, is analyzed a solar box cooker constructed and evaluated in Tanta, Egypt [1]. The experimental results that was obtained are compared with the numerical results that was obtained for the mathematical model. The case 2, is an evaluation of numerical results that was obtained for the operation of 10 hours for solar box cooker constructed in the Laboratorio de Ingenieri´a Te´rmica e Hidra´ulica Aplicada (LABINTHAP) in Me´xico City. [4] The solar box cooker is integrated by a covert that was made with double glass, this is use with two purposes, reduce the loss heat convection with outer and to generated the greenhouse effect with inner of cooker. In the inner of cooker there are a mirrors arrangement in inclined position (inner reflectors) placed in angles of 30°, 45° and 75°, these helped to reflex the solar rays in direction to the cook recipient. The recipient also received the solar rays in the upper part (lid). The mathematical model that was obtained from energetic analysis, is formed for five differential equations system no linear and the fourth Runge-Kutta method is used to resolve it. The numerical solution of the equations system is obtained with a computational software in C++. This work is a contribution to the application of numerical methods and computational for development of the solar energy used in thermal conversion equipments. The use of these techniques to solve the mathematical model is important to contribute in the evaluation and design of solar box cookers with multi-step inner reflector.

Glycemia monitoring

1998 ◽  
Vol 2 ◽  
pp. 23-30
Author(s):  
Igor Basov ◽  
Donatas Švitra
Keyword(s):  
Diabetes Mellitus ◽  
Mathematical Model ◽  
Numerical Methods ◽  
Differential Equations ◽  
Blood Sugar ◽  
Self Regulation ◽  
Physiological System ◽  
Non Linear ◽  
The Mathematical Model

Here a system of two non-linear difference-differential equations, which is mathematical model of self-regulation of the sugar level in blood, is investigated. The analysis carried out by qualitative and numerical methods allows us to conclude that the mathematical model explains the functioning of the physiological system "insulin-blood sugar" in both normal and pathological cases, i.e. diabetes mellitus and hyperinsulinism.

Numerical Simulation on Mold Electromagnetic Eccentric Stirring and Central Segregation of Round Bloom

2013 ◽  
Vol 652-654 ◽  
pp. 2450-2454
Author(s):  
Zhi Hong Zhang ◽  
Guo Guang Cheng
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Electromagnetic Stirring ◽  
Center Line ◽  
Central Segregation

The paper describes multi-section round bloom casting using external MEMS, equipped with max section D600mm and min D280mm mold, the center line of D280mm mold not coincident with the axis of stirrer coils. it is exist eccentric electromagnetic stirring of mold which section less than max D600mm, a mathematical model of MEMS has been established, the index of central segregation of D280mm macrostructure had decreased less than 1.12 by optimized parameters of electromagnetic stirring and SEN immerse depth, in the end, the quality of round bloom had improved.

Numerical modelling of swirling momentumless turbulent wake dynamics

2018 ◽  
pp. 37-48
Author(s):  
Андрей Геннадьевич Деменков ◽  
Геннадий Георгиевич Черных
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Mathematical Models ◽  
Equations Of Motion ◽  
Turbulent Wake ◽  
The Body ◽  
Jet Flows ◽  
Reynolds Stresses ◽  
Bodies Of Revolution ◽  
Averaged Equations

С применением математической модели, включающей осредненные уравнения движения и дифференциальные уравнения переноса нормальных рейнольдсовых напряжений и скорости диссипации, выполнено численное моделирование эволюции безымпульсного закрученного турбулентного следа с ненулевым моментом количества движения за телом вращения. Получено, что начиная с расстояний порядка 1000 диаметров от тела течение становится автомодельным. На основе анализа результатов численных экспериментов построены упрощенные математические модели дальнего следа. Swirling turbulent jet flows are of interest in connection with the design and development of various energy and chemical-technological devices as well as both study of flow around bodies and solving problems of environmental hydrodynamics, etc. An interesting example of such a flow is a swirling turbulent wake behind bodies of revolution. Analysis of the known works on the numerical simulation of swirling turbulent wakes behind bodies of revolution indicates lack of knowledge on the dynamics of the momentumless swirling turbulent wake. A special case of the motion of a body with a propulsor whose thrust compensates the swirl is studied, but there is a nonzero integral swirl in the flow. In previous works with the participation of the authors, a numerical simulation of the initial stage of the evolution of a swirling momentumless turbulent wake based on a hierarchy of second-order mathematical models was performed. It is shown that a satisfactory agreement of the results of calculations with the available experimental data is possible only with the use of a mathematical model that includes the averaged equations of motion and differential equations for the transfer of normal Reynolds stresses along the rate of dissipation. In the present work, based on the above mentioned mathematical model, a numerical simulation of the evolution of a far momentumless swirling turbulent wake with a nonzero angular momentum behind the body of revolution is performed. It is shown that starting from distances of the order of 1000 diameters from the body the flow becomes self-similar. Based on the analysis of the results of numerical experiments, simplified mathematical models of the far wake are constructed. The authors dedicate this work to the blessed memory of Vladimir Alekseevich Kostomakha.

MATHEMATICAL ANALYSIS OF THE ENDEMIC EQUILIBRIUM OF MALARIAHYGIENE MODEL

2021 ◽  
Vol 5 (10) ◽  
Author(s):  
Oluwafemi Temidayo J. ◽  
Azuaba E. ◽  
Lasisi N. O.
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Equilibrium Point ◽  
Reproduction Number ◽  
Endemic Equilibrium ◽  
The Mathematical Model ◽  
Globally Stable ◽  
Well Posed ◽  
The Basic Reproduction Number ◽  
Invariant Principle

In this study, we analyzed the endemic equilibrium point of a malaria-hygiene mathematical model. We prove that the mathematical model is biological and meaningfully well-posed. We also compute the basic reproduction number using the next generation method. Stability analysis of the endemic equilibrium point show that the point is locally stable if reproduction number is greater that unity and globally stable by the Lasalle’s invariant principle. Numerical simulation to show the dynamics of the compartment at various hygiene rate was carried out.

Design of Digital Filter Based on Numerical Simulation

2014 ◽  
Vol 539 ◽  
pp. 79-83
Author(s):  
Chuan Ting Wei ◽  
Quan Li Ning ◽  
Dong Chen
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Digital Filter ◽  
Sampling Frequency ◽  
New Wave ◽  
Matlab Software ◽  
Frequency Wave

In MATLAB software, it has FDATool toolbox, which can design digital filter specific according to specific circuit, and analyze the performance of the filter according to the parameters of filter. In this paper we establish simulation mathematical model of digital filter based on the calculation principle of distributed multiplication accumulator. According to the logic algorithm we design delay algorithm of digital filter, and use MATLAB software to do simulation on amplitude frequency and phase frequency of digital filter. After superposition of different sampling frequency wave we get new waveform, and realize the digital filter for the new wave. It proves the availability of mathematical model and the program, and provides the technical reference for the design of digital filter.

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