WSEAS Transactions on Applied and Theoretical Mechanics最新文献_第8页

Influence of the Moment in Mathematical Models for Open Systems 矩对开放系统数学模型的影响

WSEAS Transactions on Applied and Theoretical Mechanics Pub Date : 2021-12-16 DOI: 10.37394/232011.2021.16.28

E. Prozorova

{"title":"Influence of the Moment in Mathematical Models for Open Systems","authors":"E. Prozorova","doi":"10.37394/232011.2021.16.28","DOIUrl":"https://doi.org/10.37394/232011.2021.16.28","url":null,"abstract":"Article is proposed, built taking into account the influence of the angular momentum (force) in mathematical models of open mechanics. The speeds of various processes at the time of writing the equations were relatively small compared to modern ones. Theories have generally been developed for closed systems. As a result, in continuum mechanics, the theory developed for potential flows was expanded on flows with significant gradients of physical parameters without taking into account the combined action of force and moment. The paper substantiates the vector definition of pressure and the no symmetry of the stress tensor based on consideration of potential flows and on the basis of kinetic theory. It is proved that for structureless particles the symmetry condition for the stress tensor is one of the possible conditions for closing the system of equations. The influence of the moment is also traced in the formation of fluctuations in a liquid and in a plasma in the study of Brownian motion, Landau damping, and in the formation of nanostructures. The nature of some effects in nanostructures is discussed. The action of the moment leads to three-dimensional effects even for initially flat structures. It is confirmed that the action of the moment of force is the main source of the collective effects observed in nature. Examples of solving problems of the theory of elasticity are given.","PeriodicalId":53603,"journal":{"name":"WSEAS Transactions on Applied and Theoretical Mechanics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43018409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

An Elastic Half Space with a Moving Punch 具有移动冲头的弹性半空间

WSEAS Transactions on Applied and Theoretical Mechanics Pub Date : 2021-11-22 DOI: 10.37394/232011.2021.16.27

S. Saha, Vikash Kumar, Apurba Narayan Das

引用次数: 3

Stress Analysis of Functionally Graded Disk with Exponentially Varying Thickness using Iterative Method 用迭代法分析指数变厚度功能梯度盘的应力

WSEAS Transactions on Applied and Theoretical Mechanics Pub Date : 2021-11-09 DOI: 10.37394/232011.2021.16.26

Sandeep Kumar Paul, M. Sahni

引用次数: 2

Analytical and Numerical Solutions to Selected Research Problems in Geomechanics and Geohydraulics 岩土力学和岩土水力学若干研究问题的解析和数值解

WSEAS Transactions on Applied and Theoretical Mechanics Pub Date : 2021-10-31 DOI: 10.37394/232011.2021.16.25

S. Basack, Ghritartha Goswami, S. Nimbalkar

引用次数: 5

Mathematical Modelling and Simulation for One Dimensional - Two-Phase Flow Equation in Petroleum Reservoir: A Matlab Algorithm Approach 油层一维两相流方程的数学建模与仿真:Matlab算法方法

WSEAS Transactions on Applied and Theoretical Mechanics Pub Date : 2021-10-29 DOI: 10.37394/232011.2021.16.24

Jwngsar Brahma

{"title":"Mathematical Modelling and Simulation for One Dimensional - Two-Phase Flow Equation in Petroleum Reservoir: A Matlab Algorithm Approach","authors":"Jwngsar Brahma","doi":"10.37394/232011.2021.16.24","DOIUrl":"https://doi.org/10.37394/232011.2021.16.24","url":null,"abstract":"The reservoir behaviors described by a set of differential equation those results from combining Darcy’s law and the law of mass conservation for each phase in the system. The one-dimensional two-phase flow equation is implicit in the pressure and saturation and explicit in relative permeability. A mathematical model of a physical system is a set of partial differential equations together with an appropriate set of boundary conditions, which describes the significant physical processes taking place in that system. The processes occurring in petroleum reservoirs are fluid flow and mass transfer. Two immiscible phases (water& oil) flow simultaneously while mass transfer may take place among the phases. Gravity, capillary, and viscous forces play a role in the fluid-flow process. The model equations must account for all these forces and should also take into account an arbitrary reservoir description with respect to heterogeneity and geometry. Finally, one-dimensional two-phase flow equation through porous media is formulated by considering above reservoir parameters and forces. A numerical method based on finite difference scheme is implemented to get the solutions of one-dimensional two-phase flow equation. A MATLAB algorithm is used to solve the equation with mathematical analysis resulting in upper and lower bounds for the ratio of time step to mesh. The MATLAB algorithm is modified as per the model with appropriate initial and boundary conditions. The algorithm is applied to two-phase water flooding problems in laboratory size cores, and resulting saturation and pressure distribution are presented graphically. The saturation and pressure distribution of two-phase flow model is in agreement with the prediction of the Buckley Leveret theory. The numerical solution is used as a base for evaluating the numerical methods with respect to machine time requirement and allowable tie step for fixed mesh spacing.","PeriodicalId":53603,"journal":{"name":"WSEAS Transactions on Applied and Theoretical Mechanics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45376117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Flow of a Fluid with Pressure-Dependent Viscosity through Variable Permeability Porous Layer 粘度随压力变化的流体在变渗透多孔层中的流动

WSEAS Transactions on Applied and Theoretical Mechanics Pub Date : 2021-10-22 DOI: 10.37394/232011.2021.16.23

M. Abu Zaytoon, Y. Xiao, M. Hamdan

引用次数: 0

Thermomechanical and Tribological Properties of SiC/Gr Reinforced Hybrid Aluminum Composite for Disc Brake Application 盘式制动器用SiC/Gr复合材料的热机械性能和摩擦学性能

WSEAS Transactions on Applied and Theoretical Mechanics Pub Date : 2021-10-01 DOI: 10.37394/232011.2021.16.20

D. Rahmalina, H. Sukma, A. Suhadi

{"title":"Thermomechanical and Tribological Properties of SiC/Gr Reinforced Hybrid Aluminum Composite for Disc Brake Application","authors":"D. Rahmalina, H. Sukma, A. Suhadi","doi":"10.37394/232011.2021.16.20","DOIUrl":"https://doi.org/10.37394/232011.2021.16.20","url":null,"abstract":"The disc brake motorcycle material has been developed by using aluminium matrix composite (AMC) reinforced with matrix particulate ceramic. The composite has many advantages: lightweight, high re-sistance to wear, and controllable strength by adjusting the reinforcement materials percentage. The main issue is the environmental factor that influences the surface properties of the disc. The research aims to study thermomechanical and tribology characteristics to determine the effect of the environmental factor on the composite's wear-out rate. The disc is made from matrix Al7Si6Mg9Zn composite matrix with 10% SiC and 10% graphite (v/v). The disc is produced by squeeze casting method and heated for 4 hours at 180 °C as artificial aging heat treatment. Thermomechanical characteristics are carried out by observing the temperature changes when a load is introduced to the disc. The pin-on-disc method is applied at three different speeds (60, 80, and 100 rpm) under the wet and dry surface on the disc for observing the tribo-logical properties. Thermomechanical characteristics of the disc are average braking time is 3.72 seconds, where the average braking distance is 515.8 cm at speed 40 km/hour with the average temperature of 46.12 °C. The wear-out rate results are steady, where the highest wear out rate for the dry surface is 0.725 mm3/N.m and 6.133 mm3/N.m for the wet surface at 100 rpm.","PeriodicalId":53603,"journal":{"name":"WSEAS Transactions on Applied and Theoretical Mechanics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48549882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Modified Model Reference Adaptive Control for High-Performance Pantograph Robot Mechanism 高性能受电弓机器人机构的改进模型参考自适应控制

WSEAS Transactions on Applied and Theoretical Mechanics Pub Date : 2021-10-01 DOI: 10.37394/232011.2021.16.22

Layla M. El-Τehewy, Mohamed A. Shamseldin, M. Sallam, Α. M. A. Ghany

{"title":"A Modified Model Reference Adaptive Control for High-Performance Pantograph Robot Mechanism","authors":"Layla M. El-Τehewy, Mohamed A. Shamseldin, M. Sallam, Α. M. A. Ghany","doi":"10.37394/232011.2021.16.22","DOIUrl":"https://doi.org/10.37394/232011.2021.16.22","url":null,"abstract":"Pantograph Robot Mechanism is considered a type of parallel manipulator which has been developed largely for industrial applications that need high accuracy and speed. Whereas, it needs a high-performance controller to track preselected trajectory planning. It is also able to carry higher weights than the open-chain mechanism with suitable accuracy and stability; this is because it consists of four active links and one passive link, instead of two links as in the open chain. This study presents a mathematical model for a closed chain pantograph mechanism, where the boundary conditions are taken into account. A complete MATLAB Simulink has been developed to simulate the dynamics of the pantograph robot mechanism. To validate the proposed mathematical model of the pantograph, the corresponding Simscape model had been developed. Also, three different tracking controllers were designed. The first control is the PID controller which had optimized by Flower Pollination (FP) optimization. The second control is an enhanced Nonlinear PID (NLPID) controller where its parameters were obtained by Flower Pollination (FP) optimization based on the effective objective function. The third control is the model reference adaptive control. A comparative study between the control techniques was accomplished. A rectangular trajectory was selected to be a position reference of the end effector of the pantograph robot. This task was done using the proposed controllers to investigate the performance. The results show that the model reference adaptive control has a better performance compared to the NLPID and PID controllers. The end effector has a less rise time and settling time with high accuracy in the case of the model reference adaptive control.","PeriodicalId":53603,"journal":{"name":"WSEAS Transactions on Applied and Theoretical Mechanics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46078897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Study of Electrokinetic Properties of Magnetite – Silica Core – Shell Nanoparticles 磁铁矿-二氧化硅核-壳纳米颗粒的电动力学性质研究

WSEAS Transactions on Applied and Theoretical Mechanics Pub Date : 2021-09-16 DOI: 10.37394/232011.2021.16.19

Y. Utkin, Minggong Sha

{"title":"Study of Electrokinetic Properties of Magnetite – Silica Core – Shell Nanoparticles","authors":"Y. Utkin, Minggong Sha","doi":"10.37394/232011.2021.16.19","DOIUrl":"https://doi.org/10.37394/232011.2021.16.19","url":null,"abstract":"In this work, the electrokinetic properties of Fe3O4 nanoparticles modified with various alkoxysilanes (tetraethoxysilane and 3-aminopropyltriethoxysilane) in various media were investigated. The determined values of the zeta potential of the Fe3O4/SiO2 samples indicate the complete coverage of nanoparticles with a tetraethoxysilane shell, as well as in the case of the Fe3O4/aminopropyltriethoxysilane. The data obtained on the zeta-potentials of modified nanoparticles with various ligands make it possible to predict the efficiency of subsequent functionalization by target molecules. A decisive role in the study of surface properties is played by cleaning from low molecular weight impurities that can screen the surface of nanoparticles or bind with an indifferent electrolyte. Thus, dispersion on a magnetic stirrer leads to an increase in the sorption capacity of the sample in comparison with ultrasonic dispersion, which causes irreversible destruction of the core-shell nanoparticle structure due to an increase in temperature and pressure in the cavities. This opens the prospective for practical application of modified nanoparticles for creation of tailored composite materials.","PeriodicalId":53603,"journal":{"name":"WSEAS Transactions on Applied and Theoretical Mechanics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44160201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Investigation of Adsorption Capacity of Magnetite Nanoparticles 磁性纳米粒子吸附性能的研究

WSEAS Transactions on Applied and Theoretical Mechanics Pub Date : 2021-09-16 DOI: 10.37394/232011.2021.16.18

V. Rodchenko, Kyaw Ye Ko

{"title":"Investigation of Adsorption Capacity of Magnetite Nanoparticles","authors":"V. Rodchenko, Kyaw Ye Ko","doi":"10.37394/232011.2021.16.18","DOIUrl":"https://doi.org/10.37394/232011.2021.16.18","url":null,"abstract":"In this work, the preparation of Fe3O4 nanoparticles modified with 3-aminopropyltriethoxysilane (APTES) was carried out under various synthesis modes (in air or in argon). The zeta potential and hydrodynamic diameter of Fe3O4-APTES nanoparticles were determined by the method of dynamic and electrokinetic light scattering. The effect of humic acids on the zeta potential, hydrodynamic diameter and colloidal stability of Fe3O4-APTES at different pH values was established by the method of dynamic and electrophoretic light scattering. It has been shown that changes in the conditions of the synthesis of nanoparticles of one component composition Fe3O4-APTES (argon) and Fe3O4-APTES (air) (in an inert medium and in an air atmosphere, respectively) lead to a change in the charge of the particle surface and a subsequent change in the sorption properties with respect to HA. It was demonstrated that the decisive role in the study of surface properties is played by the purification from low-molecular-weight impurities that can screen the surface of nanoparticles or bind with an indifferent electrolyte. The stage of dispersive post-preparation of samples is also important for the correct determination of the sorption capacity and hydrodynamic diameter of particles.","PeriodicalId":53603,"journal":{"name":"WSEAS Transactions on Applied and Theoretical Mechanics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49296984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2