IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Alternative and Explicit Derivation of the Lattice Boltzmann Equation for the...ijceronline
A lattice Boltzmann equation for fully incompressible flows is derived through the utilization of appropriate ansatzes. The result is a singular equilibrium distribution function which clarifies the algorithm for general implementation, and ensures correct steady and unsteady behavior. Through the Chapman-Enskog expansion, the exact incompressible Navier-Stokes equations are recovered. With 2D and 3D canonical numerical simulations, the application, accuracy, and workable boundary conditions are shown. Several unique benefits over the standard equation and alternative forms presented in literature are found, including faster convergence rate and greater stability.
We know that the molecules vibrate with characteristic frequencies. These frequencies match to the IR region of electromagnetic radiation, and Molecular vibrations are nothing but the relative motions of atoms with respect to each other.
Thus molecular vibrations actually define the energy states of the molecules.Group theory can help us to identify which molecular vibrations can really exist.
This document discusses inverting the Dirac equation for the vector potential in the non-abelian SU(2) case. It first reviews the abelian U(1) case and shows how the vector potential can be written as a rational expression of Dirac bispinor current densities. For the non-abelian SU(2) case, the Dirac equation is set up for an SU(2) doublet spinor. An "isospin-charge conjugation" operator is defined to make the gauge potential covariant, but inverting the equation only yields the vector potential as a Neumann series involving Pauli scalar and vector current densities. Fierz identities are also derived to express skew tensor current densities solely in terms of
This document summarizes the development of a numerical method to estimate the static solution of peridynamic models from their dynamic response. The method involves fitting ellipses to points in the Lyapunov diagram generated during a dynamic simulation and taking the center of the ellipse as the estimated static solution. Three test scenarios are used to validate the method, showing it can accurately estimate the static deformation of 1D and 2D systems under different loading conditions from a limited dynamic simulation. Future work is outlined to model material damage and compare with alternative solution methods.
AN IMPLEMENTATION FOR FRAMEWORK FOR CHEMICAL STRUCTURE USING GRAPH GRAMMAR | ...Journal For Research
Modeling molecules as undirected graphs and chemical reactions as graph rewriting operations is a natural and convenient approach to modeling chemistry. Graph grammar rules are most naturally employed to model elementary reactions like merging, splitting, and isomerisation of molecules. In this paper a generic approach for composing graph grammar rules to define a chemically useful rule compositions. We iteratively apply these rule compositions to elementary transformations in order to automatically infer complex transformation patterns.
The unexpected fractal signatures in fibonacci chains 10.06.16 - final - ff Klee Irwin
This paper analyzes the fractal properties of a one-dimensional Fibonacci chain in Fourier space. The authors find that plotting successive iterations of the Fibonacci chain reveals a cardioid shape, resembling the main pattern in the Mandelbrot set. This cardioid decreases in size following each iteration by approximately half the golden ratio. Minor modifications to the Fibonacci chain disrupt this pattern, showing it depends precisely on the substitution rules used to generate the chain. Only changing the ratio of segment lengths preserves the pattern's scaling. This fractal signature may correspond to quasiperiodic gearing in a geometric chuck that can draw similar cycloidal shapes.
This section discusses stiffness analysis for grasping tasks. It defines stiffness as the property of resisting deformation from an applied load. Stiffness is important for grasping stability and accuracy. The section describes modeling robotic systems' stiffness through a Cartesian stiffness matrix that relates external forces to compliant displacements. It presents methods to compute the stiffness matrix using lumped parameter models of link and joint stiffnesses. Examples of lumped parameter models are shown for different robotic systems, grippers and hands. The analysis of stiffness is important for design, control and experimental validation of robotic systems for grasping.
2D Shape Reconstruction Based on Combined Skeleton-Boundary FeaturesCSCJournals
This paper proposes a new method for 2D shape reconstruction based on combining skeleton and boundary features. The method aims to mimic human perceptual processes by using both curvature properties of the shape boundary and structural properties of the shape skeleton. Junction points on the skeleton are used to identify likely protrusions, while boundary features like curvature, length and width are used to determine the strength of protrusions. Experiments show the reconstructed shapes match human perceptual judgments better than existing methods. The approach gives a stable reconstruction and is robust to noise.
Alternative and Explicit Derivation of the Lattice Boltzmann Equation for the...ijceronline
A lattice Boltzmann equation for fully incompressible flows is derived through the utilization of appropriate ansatzes. The result is a singular equilibrium distribution function which clarifies the algorithm for general implementation, and ensures correct steady and unsteady behavior. Through the Chapman-Enskog expansion, the exact incompressible Navier-Stokes equations are recovered. With 2D and 3D canonical numerical simulations, the application, accuracy, and workable boundary conditions are shown. Several unique benefits over the standard equation and alternative forms presented in literature are found, including faster convergence rate and greater stability.
We know that the molecules vibrate with characteristic frequencies. These frequencies match to the IR region of electromagnetic radiation, and Molecular vibrations are nothing but the relative motions of atoms with respect to each other.
Thus molecular vibrations actually define the energy states of the molecules.Group theory can help us to identify which molecular vibrations can really exist.
This document discusses inverting the Dirac equation for the vector potential in the non-abelian SU(2) case. It first reviews the abelian U(1) case and shows how the vector potential can be written as a rational expression of Dirac bispinor current densities. For the non-abelian SU(2) case, the Dirac equation is set up for an SU(2) doublet spinor. An "isospin-charge conjugation" operator is defined to make the gauge potential covariant, but inverting the equation only yields the vector potential as a Neumann series involving Pauli scalar and vector current densities. Fierz identities are also derived to express skew tensor current densities solely in terms of
This document summarizes the development of a numerical method to estimate the static solution of peridynamic models from their dynamic response. The method involves fitting ellipses to points in the Lyapunov diagram generated during a dynamic simulation and taking the center of the ellipse as the estimated static solution. Three test scenarios are used to validate the method, showing it can accurately estimate the static deformation of 1D and 2D systems under different loading conditions from a limited dynamic simulation. Future work is outlined to model material damage and compare with alternative solution methods.
AN IMPLEMENTATION FOR FRAMEWORK FOR CHEMICAL STRUCTURE USING GRAPH GRAMMAR | ...Journal For Research
Modeling molecules as undirected graphs and chemical reactions as graph rewriting operations is a natural and convenient approach to modeling chemistry. Graph grammar rules are most naturally employed to model elementary reactions like merging, splitting, and isomerisation of molecules. In this paper a generic approach for composing graph grammar rules to define a chemically useful rule compositions. We iteratively apply these rule compositions to elementary transformations in order to automatically infer complex transformation patterns.
The unexpected fractal signatures in fibonacci chains 10.06.16 - final - ff Klee Irwin
This paper analyzes the fractal properties of a one-dimensional Fibonacci chain in Fourier space. The authors find that plotting successive iterations of the Fibonacci chain reveals a cardioid shape, resembling the main pattern in the Mandelbrot set. This cardioid decreases in size following each iteration by approximately half the golden ratio. Minor modifications to the Fibonacci chain disrupt this pattern, showing it depends precisely on the substitution rules used to generate the chain. Only changing the ratio of segment lengths preserves the pattern's scaling. This fractal signature may correspond to quasiperiodic gearing in a geometric chuck that can draw similar cycloidal shapes.
This section discusses stiffness analysis for grasping tasks. It defines stiffness as the property of resisting deformation from an applied load. Stiffness is important for grasping stability and accuracy. The section describes modeling robotic systems' stiffness through a Cartesian stiffness matrix that relates external forces to compliant displacements. It presents methods to compute the stiffness matrix using lumped parameter models of link and joint stiffnesses. Examples of lumped parameter models are shown for different robotic systems, grippers and hands. The analysis of stiffness is important for design, control and experimental validation of robotic systems for grasping.
2D Shape Reconstruction Based on Combined Skeleton-Boundary FeaturesCSCJournals
This paper proposes a new method for 2D shape reconstruction based on combining skeleton and boundary features. The method aims to mimic human perceptual processes by using both curvature properties of the shape boundary and structural properties of the shape skeleton. Junction points on the skeleton are used to identify likely protrusions, while boundary features like curvature, length and width are used to determine the strength of protrusions. Experiments show the reconstructed shapes match human perceptual judgments better than existing methods. The approach gives a stable reconstruction and is robust to noise.
El documento describe tres modalidades educativas: la educación presencial, la educación formal o escolarizada, y las TIC's que pueden integrarse a estas modalidades. La educación presencial se caracteriza por centrarse en el docente y por usar recursos como la pizarra, mientras que los estudiantes son observadores. La educación formal o escolarizada es un sistema institucionalizado estructurado jerárquicamente que va de la primaria a la universidad. El documento también incluye un mapa conceptual sobre estas modalidades.
Este documento discute a automação de testes em projetos ágeis. Ele descreve como os testes ágeis são integrados ao processo de desenvolvimento, frequentemente automatizados, e realizados em todas as camadas do sistema. Além disso, explica como técnicas como testes unitários, BDD e ferramentas como Cucumber e Pyccuracy podem ser usadas para automatizar testes funcionais e de aceitação de forma a apoiar a entrega contínua em metodologias ágeis.
Este documento resume una copla anónima dedicada a la muerte del padre del autor. La copla expresa que aunque el hombre quiera vivir, debe aceptar su muerte cuando Dios así lo quiera, pues oponerse sería una locura. El poema usa varios versos como heptasílabos y cuartetos para transmitir el mensaje de vivir la vida sin quejarse y morir contento aunque no se quiera morir.
La Unión Europea ha acordado un paquete de sanciones contra Rusia por su invasión de Ucrania. Las sanciones incluyen restricciones a las importaciones de productos rusos de alta tecnología y a las exportaciones de bienes de lujo a Rusia. Además, se congelarán los activos de varios oligarcas rusos y se prohibirá el acceso de los bancos rusos a los mercados financieros de la UE.
El documento describe diferentes tipos de redes informáticas, incluyendo redes públicas, privadas, de área personal, de área local, de área amplia y más. Explica la clasificación, características y usos de cada tipo de red. También cubre temas como protocolos TCP/IP, sistema de nombres de dominio, topologías de redes e historia de Internet.
Este documento resume as atividades e eventos ocorridos ao longo do ano letivo na EB1 do Pinheiral. As crianças fizeram visitas, desfiles, jogos, e trabalhos sobre temas como a Europa, alimentação saudável e o Galo de Barcelos. Elas também apreciaram apresentações de polícia, ilustradores e alunos de escola secundária.
1) Etnocentrismo é uma atitude em que um grupo sempre se vê como superior aos outros com base nos seus próprios valores e padrões.
2) Não há grupos realmente superiores ou inferiores, mas sim com diferentes desenvolvimentos e adaptações a seus ambientes.
3) A escola reúne pessoas de diferentes origens e o etnocentrismo se manifesta quando consideramos apenas nossos pontos de vista como válidos.
Ponencia de Patricia Gómez, de Iberdrola, en la jornada sobre "Los caudales ecológicos en la demarcación hidrográfica del Tajo", organizada por la FNCA, la Universidad Autónoma de Madrid y la Universidad Politécnica de Madrid.
Alberto Garrido y Bárbara Wilaarts y la huella hídrica en el VII Congreso Ibé...Nueva Cultura del Agua
El documento presenta conceptos sobre la huella hídrica y su aplicación para evaluar el comercio de agua virtual. Se define la huella hídrica como la cantidad de agua dulce utilizada directa o indirectamente para producir bienes y servicios. Se analizan casos como la huella hídrica de España y la producción de tomate, así como las implicaciones ambientales del comercio de agua virtual a través de la producción de soja en Brasil. Se concluye que la huella hídrica es un indicador útil pero no suficiente para la toma de
O documento fornece instruções para criar uma conta de armazenamento no Windows Azure e publicar arquivos nela usando o Blob Uploader no Visual Studio. Ele explica como baixar e usar o Blob Uploader para fazer upload de uma imagem JPG para um blob público usando os detalhes da conta recém-criada no Azure.
La Primera Guerra Mundial fue un conflicto devastador que involucró a la mayor parte de Europa y otras regiones. Tras la guerra, los aliados intentaron establecer la paz a través de tratados como el de Versalles y la creación de la Sociedad de Naciones. No obstante, las tensiones persistieron debido a problemas como las reparaciones de guerra a Alemania, lo que eventualmente llevó al estallido de otra guerra.
El documento presenta un recurso interactivo para que estudiantes entre 10 y 13 años tomen decisiones que contribuyan a la paz y armonía social. El recurso ofrece escenarios comunes con situaciones que requieren una decisión, y evalúa las consecuencias de las opciones para promover valores como la solidaridad y justicia.
D. Afonso Henriques foi um rei de Portugal que conquistou muitas terras e venceu muitas batalhas dentro do castelo em Guimarães, onde foi criado. Ele lutava com coragem e vontade e se tornou um verdadeiro rei. D. Afonso Henriques também foi batizado na capela onde tudo era espetacular.
Duas crianças estavam patinando em um lago congelado na Alemanha quando o gelo quebrou e uma caiu na água. A outra criança conseguiu quebrar o gelo com um patim e resgatar o amigo. Quando perguntado como fez isso, Einstein explicou que a criança conseguiu porque ninguém disse que ela não poderia.
O documento descreve a história de Canudos, um assentamento fundado por Antonio Conselheiro no interior da Bahia no século 19. Centenas de pessoas seguiram o Conselheiro em busca de terra prometida por Deus. No entanto, o governo republicano enviou tropas para dizimar a cidade, alegando que o Conselheiro era monarquista. Apesar disso, o movimento dos Sem Terra no século 21 continua lutando por terras improdutivas, assim como Conselheiro outrora.
Este documento resume el Plan Hidrológico de la Demarcación del Guadalquivir. Los objetivos son conseguir el buen estado de las masas de agua y satisfacer las demandas de agua de forma sostenible. Actualmente existe contaminación por vertidos urbanos e industriales, así como por nitratos y fitosanitarios agrícolas. También hay problemas de erosión y afecciones hidromorfológicas. El documento propone medidas como mejorar el tratamiento de aguas residuales, aplicar buenas prácticas agrarias y restaurar ecos
Este documento presenta un proyecto de Photoshop para crear la identidad de un personaje militar y hacer un fotomontaje. El objetivo es representar a un militar saliendo de un pantano lleno de humo y sufriendo dolor por una herida de bala. Se proporcionan ideas y ejemplos para la identidad del personaje, como militar, dolor y humo. Luego, se describe al personaje como un militar con camuflaje verde opaco, casco y rifle, sufriendo dolor después de recibir un bala y estar en un pant
Este documento presenta una guía para estudiantes de primaria sobre cómo tratarse bien los unos a los otros y evitar el maltrato. Explica qué comportamientos constituyen maltrato como pelearse, insultar o excluir a otros, y destaca la importancia de respetar los derechos y responsabilidades de cada persona. Además, ofrece consejos sobre qué hacer si se es víctima o testigo de maltrato y la necesidad de resolver los conflictos de forma pacífica.
Influence of joint clearance on kinematic and dynamic parameters of mechanismIOSR Journals
Kinematic joints for dynamic analysis of multi-body mechanical systems assumed ideal or perfect.
However, in a real mechanical kinematical joint clearance is always present. Such clearance is necessary for
the component assemblage and to allow the relative motion between the connected bodies. This clearance is
inevitable due to the manufacturing tolerances, material deformations, wear, and imperfections. The presence of
such joint clearance degrades the performance of mechanical systems in virtue of the contact and impact forces
that take place at the joint. Contact analysis is a computational bottleneck in mechanical design where the
contact changes. Manual analysis is time-consuming and prone to error. To address these problems, a
geometrical contact analysis method based on kinematic simulation, using CAD software is developed. An
equivalent kinematic linkage mechanism is constructed according to contact position of pin and hole assembly.
Results of kinematic and dynamic analysis of a four bar linkage with joint clearance shows that the contribution
of joint forces at slower input speed also degrades the performance of mechanism
This document discusses stiffness analysis of flexible parallel manipulators. It presents the forward kinematics analysis of a 3-RRR planar parallel manipulator using genetic algorithms and neural networks to minimize positional errors. The Jacobian and platform stiffness matrices are evaluated within the defined workspace. A pseudo-rigid body model with frame and plate elements is used to analyze the flexible link configuration and compliant joints. Stiffness indices are obtained and validated using commercial finite element software. The methodology is illustrated for a 3-RRR flexible parallel manipulator to study the effects of link flexibility and joint compliance on stiffness.
El documento describe tres modalidades educativas: la educación presencial, la educación formal o escolarizada, y las TIC's que pueden integrarse a estas modalidades. La educación presencial se caracteriza por centrarse en el docente y por usar recursos como la pizarra, mientras que los estudiantes son observadores. La educación formal o escolarizada es un sistema institucionalizado estructurado jerárquicamente que va de la primaria a la universidad. El documento también incluye un mapa conceptual sobre estas modalidades.
Este documento discute a automação de testes em projetos ágeis. Ele descreve como os testes ágeis são integrados ao processo de desenvolvimento, frequentemente automatizados, e realizados em todas as camadas do sistema. Além disso, explica como técnicas como testes unitários, BDD e ferramentas como Cucumber e Pyccuracy podem ser usadas para automatizar testes funcionais e de aceitação de forma a apoiar a entrega contínua em metodologias ágeis.
Este documento resume una copla anónima dedicada a la muerte del padre del autor. La copla expresa que aunque el hombre quiera vivir, debe aceptar su muerte cuando Dios así lo quiera, pues oponerse sería una locura. El poema usa varios versos como heptasílabos y cuartetos para transmitir el mensaje de vivir la vida sin quejarse y morir contento aunque no se quiera morir.
La Unión Europea ha acordado un paquete de sanciones contra Rusia por su invasión de Ucrania. Las sanciones incluyen restricciones a las importaciones de productos rusos de alta tecnología y a las exportaciones de bienes de lujo a Rusia. Además, se congelarán los activos de varios oligarcas rusos y se prohibirá el acceso de los bancos rusos a los mercados financieros de la UE.
El documento describe diferentes tipos de redes informáticas, incluyendo redes públicas, privadas, de área personal, de área local, de área amplia y más. Explica la clasificación, características y usos de cada tipo de red. También cubre temas como protocolos TCP/IP, sistema de nombres de dominio, topologías de redes e historia de Internet.
Este documento resume as atividades e eventos ocorridos ao longo do ano letivo na EB1 do Pinheiral. As crianças fizeram visitas, desfiles, jogos, e trabalhos sobre temas como a Europa, alimentação saudável e o Galo de Barcelos. Elas também apreciaram apresentações de polícia, ilustradores e alunos de escola secundária.
1) Etnocentrismo é uma atitude em que um grupo sempre se vê como superior aos outros com base nos seus próprios valores e padrões.
2) Não há grupos realmente superiores ou inferiores, mas sim com diferentes desenvolvimentos e adaptações a seus ambientes.
3) A escola reúne pessoas de diferentes origens e o etnocentrismo se manifesta quando consideramos apenas nossos pontos de vista como válidos.
Ponencia de Patricia Gómez, de Iberdrola, en la jornada sobre "Los caudales ecológicos en la demarcación hidrográfica del Tajo", organizada por la FNCA, la Universidad Autónoma de Madrid y la Universidad Politécnica de Madrid.
Alberto Garrido y Bárbara Wilaarts y la huella hídrica en el VII Congreso Ibé...Nueva Cultura del Agua
El documento presenta conceptos sobre la huella hídrica y su aplicación para evaluar el comercio de agua virtual. Se define la huella hídrica como la cantidad de agua dulce utilizada directa o indirectamente para producir bienes y servicios. Se analizan casos como la huella hídrica de España y la producción de tomate, así como las implicaciones ambientales del comercio de agua virtual a través de la producción de soja en Brasil. Se concluye que la huella hídrica es un indicador útil pero no suficiente para la toma de
O documento fornece instruções para criar uma conta de armazenamento no Windows Azure e publicar arquivos nela usando o Blob Uploader no Visual Studio. Ele explica como baixar e usar o Blob Uploader para fazer upload de uma imagem JPG para um blob público usando os detalhes da conta recém-criada no Azure.
La Primera Guerra Mundial fue un conflicto devastador que involucró a la mayor parte de Europa y otras regiones. Tras la guerra, los aliados intentaron establecer la paz a través de tratados como el de Versalles y la creación de la Sociedad de Naciones. No obstante, las tensiones persistieron debido a problemas como las reparaciones de guerra a Alemania, lo que eventualmente llevó al estallido de otra guerra.
El documento presenta un recurso interactivo para que estudiantes entre 10 y 13 años tomen decisiones que contribuyan a la paz y armonía social. El recurso ofrece escenarios comunes con situaciones que requieren una decisión, y evalúa las consecuencias de las opciones para promover valores como la solidaridad y justicia.
D. Afonso Henriques foi um rei de Portugal que conquistou muitas terras e venceu muitas batalhas dentro do castelo em Guimarães, onde foi criado. Ele lutava com coragem e vontade e se tornou um verdadeiro rei. D. Afonso Henriques também foi batizado na capela onde tudo era espetacular.
Duas crianças estavam patinando em um lago congelado na Alemanha quando o gelo quebrou e uma caiu na água. A outra criança conseguiu quebrar o gelo com um patim e resgatar o amigo. Quando perguntado como fez isso, Einstein explicou que a criança conseguiu porque ninguém disse que ela não poderia.
O documento descreve a história de Canudos, um assentamento fundado por Antonio Conselheiro no interior da Bahia no século 19. Centenas de pessoas seguiram o Conselheiro em busca de terra prometida por Deus. No entanto, o governo republicano enviou tropas para dizimar a cidade, alegando que o Conselheiro era monarquista. Apesar disso, o movimento dos Sem Terra no século 21 continua lutando por terras improdutivas, assim como Conselheiro outrora.
Este documento resume el Plan Hidrológico de la Demarcación del Guadalquivir. Los objetivos son conseguir el buen estado de las masas de agua y satisfacer las demandas de agua de forma sostenible. Actualmente existe contaminación por vertidos urbanos e industriales, así como por nitratos y fitosanitarios agrícolas. También hay problemas de erosión y afecciones hidromorfológicas. El documento propone medidas como mejorar el tratamiento de aguas residuales, aplicar buenas prácticas agrarias y restaurar ecos
Este documento presenta un proyecto de Photoshop para crear la identidad de un personaje militar y hacer un fotomontaje. El objetivo es representar a un militar saliendo de un pantano lleno de humo y sufriendo dolor por una herida de bala. Se proporcionan ideas y ejemplos para la identidad del personaje, como militar, dolor y humo. Luego, se describe al personaje como un militar con camuflaje verde opaco, casco y rifle, sufriendo dolor después de recibir un bala y estar en un pant
Este documento presenta una guía para estudiantes de primaria sobre cómo tratarse bien los unos a los otros y evitar el maltrato. Explica qué comportamientos constituyen maltrato como pelearse, insultar o excluir a otros, y destaca la importancia de respetar los derechos y responsabilidades de cada persona. Además, ofrece consejos sobre qué hacer si se es víctima o testigo de maltrato y la necesidad de resolver los conflictos de forma pacífica.
Influence of joint clearance on kinematic and dynamic parameters of mechanismIOSR Journals
Kinematic joints for dynamic analysis of multi-body mechanical systems assumed ideal or perfect.
However, in a real mechanical kinematical joint clearance is always present. Such clearance is necessary for
the component assemblage and to allow the relative motion between the connected bodies. This clearance is
inevitable due to the manufacturing tolerances, material deformations, wear, and imperfections. The presence of
such joint clearance degrades the performance of mechanical systems in virtue of the contact and impact forces
that take place at the joint. Contact analysis is a computational bottleneck in mechanical design where the
contact changes. Manual analysis is time-consuming and prone to error. To address these problems, a
geometrical contact analysis method based on kinematic simulation, using CAD software is developed. An
equivalent kinematic linkage mechanism is constructed according to contact position of pin and hole assembly.
Results of kinematic and dynamic analysis of a four bar linkage with joint clearance shows that the contribution
of joint forces at slower input speed also degrades the performance of mechanism
This document discusses stiffness analysis of flexible parallel manipulators. It presents the forward kinematics analysis of a 3-RRR planar parallel manipulator using genetic algorithms and neural networks to minimize positional errors. The Jacobian and platform stiffness matrices are evaluated within the defined workspace. A pseudo-rigid body model with frame and plate elements is used to analyze the flexible link configuration and compliant joints. Stiffness indices are obtained and validated using commercial finite element software. The methodology is illustrated for a 3-RRR flexible parallel manipulator to study the effects of link flexibility and joint compliance on stiffness.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
2-Dimensional and 3-Dimesional Electromagnetic Fields Using Finite element me...IOSR Journals
This document describes using the finite element method to model 2D and 3D electromagnetic fields. It discusses modeling a quarter section of a rectangular coaxial line with triangular elements. It describes constructing the matrices for each element and combining them to solve the overall matrix equation. The document outlines implementing FEM in MATLAB, including generating meshes, adding sources, and solving the resulting matrices. Several examples are presented of using a graphical user interface created in MATLAB to calculate fields from configurations like straight wires, bent wires, solenoids, and square loops using FEM techniques.
Research on Contact Characteristics between Bump End Effector and WaferIJRES Journal
In the IC industry, commonly used methods are wafer clamping friction transmission type and vacuum suction. Combining science and theological contact theory,the contact friction transmission characteristics when using the bump and transmission actuator wafer, the wafer and the end actuators. Starting from the material properties of the wafer by ANSYS simulation analysis in contact with the wafer bump deformation due to its own gravity, and verify that it meets the requirements of small deformation wafer transfer. Compute and solve the friction contact with the wafer bump bristles between.
This document discusses the optimal synthesis of four-bar linkages to generate a desired path. It describes using the gradient descent optimization algorithm to minimize the sum of squared errors between target precision points and points reached by the coupler link. The key constraints considered are Grashof's criterion, input link angle order, and transmission angle. A computer program implements gradient descent in MATLAB to determine the optimal four-bar linkage dimensions.
This document provides an overview of manipulator kinematics. It defines key terms like links, joints, frames and parameters used to describe the geometric relationship between links of a manipulator. Links are the rigid bodies that make up the manipulator chain. Joints connect neighboring links and allow relative motion. Frames are attached to each link to define its position and orientation. Parameters like link length, twist, and offset are used to relate the frames between links. The document provides examples of applying the Denavit-Hartenberg parameter convention to determine the kinematic description of simple manipulators. Standard frames like the base, wrist, tool and goal frames are also defined to describe the relationship between the robot and its workspace.
Human Arm Inverse Kinematic Solution Based Geometric Relations and Optimizati...Waqas Tariq
Kinematics for robotic systems with many degrees of freedom (DOF) and high redundancy are still an open issue. Namely, computation time in robotic applications is often too high to reach good solution, for parts of the kinematic chain; the problem of inverse kinematics is not linear, as rotations are involved. This means that analytical solutions are only available in limited situations. In all other cases, alternative methods will have to be an employed.The most-used alternative is numerical solutions optimization. This paper presents a strategy based on combine’s analytical solutions with nonlinear optimization algorithm solutions to solution the IKP. A analytical solutions is used to reduce the size of problem from seven variable of joint angle to single variable and nonlinear optimization algorithm was used to find approximate solution which make the computation time is very small
This document investigates how changing the position of the tool point on the moving platform affects the dynamic performance of a 3RRR planar parallel manipulator. Lagrange-d'Alembert formulation is used to develop the dynamic model. The manipulator's dimensions and parameters remain the same, while only the tool point position is changed. Simulation results show that locating the tool point at an optimal position reduces the generalized forces and energy consumption of the manipulator, improving its dynamic performance.
This document summarizes the key topics covered in Lecture 12 on constitutive relations for orthotropic materials:
1. It defines the principal material directions for orthotropic materials like unidirectional fiber laminates.
2. It describes how to determine the engineering constants like Young's modulus and Poisson's ratio from experimental tests on orthotropic materials.
3. It presents the constitutive equations that relate stress and strain for orthotropic materials using the compliance matrix, in terms of the measured engineering constants. Constraints on the engineering constants due to thermodynamic requirements are also discussed.
This document reviews research on magneto-rheological (MR) and electro-rheological (ER) fluids. It discusses the properties of MR fluids and their behavior with and without an external magnetic field. It also describes common models used to characterize MR fluids, including the Bingham plastic and Herschel-Bulkley models. The document then summarizes several research papers on topics like modeling MR fluid behavior, optimizing MR damper design using computational fluid dynamics, developing control systems for MR dampers in artillery gun recoils, and performing experiments to validate theoretical MR damper models. It concludes that damping force in MR dampers depends non-linearly on fluid properties and applied magnetic fields, and is influenced by parameters
This document provides an introduction to tensor calculus. It begins with definitions of tensors and coordinate systems. Section 1 defines tensors and contravariant and covariant indices. Section 2 focuses on Cartesian tensors and introduces tensor notation rules. It defines tensor terms, expressions, and operations. Section 3 will cover general curvilinear coordinates and covariant differentiation. The document establishes the foundation for working with tensors and their transformation properties.
This document summarizes a study that used the Reproducing Kernel Particle Method (RKPM) to simulate the penetration of thick metal structures by rigid penetrators. RKPM is a meshfree method that was used with a particle-to-segment contact algorithm for contact detection and constraints. 2D and 3D simulations of penetration were performed and showed that RKPM can simulate large deformations without remeshing, unlike finite element methods. The effectiveness of RKPM for simulating large deformations was confirmed, though future work could include modeling mechanical fracture.
Analytic parametric equations of log-aesthetic curves in terms of incomplete ...Rushan Ziatdinov
Rushan Ziatdinov, Norimasa Yoshida, Tae-wan Kim, 2012. Analytic parametric equations of log-aesthetic curves in terms of incomplete gamma functions, Computer Aided Geometric Design 29(2), 129-140.
Log-aesthetic curves (LACs) have recently been developed to meet the requirements of industrial design for visually pleasing shapes. LACs are defined in terms of definite integrals, and adaptive Gaussian quadrature can be used to obtain curve segments. To date, these integrals have only been evaluated analytically for restricted values (0, 1, 2) of the shape parameter. We present parametric equations expressed in terms of incomplete gamma functions, which allow us to find an exact analytic representation of a curve segment for any real value of alpha. The computation time for generating a LAC segment using the incomplete gamma functions is up to 13 times faster than using direct numerical integration. Our equations are generalizations of the well-known Cornu, Nielsen, and logarithmic spirals, and involutes of a circle.
This document provides a summary of a master's thesis that analyzes smart composite beams using a meshfree method. The objectives of the project are to define shape function construction for meshfree methods, derive the solution for smart composite beams, and compare the meshfree method results to exact solutions for three-layered and four-layered composite beams. The document introduces meshfree methods, describes the moving least squares shape functions used, and presents the analysis of smart composite beams by deriving the governing equations and compatible displacement fields for the substrate beam and piezoelectric layer.
Position analysis and dimensional synthesisPreetshah1212
This document provides an overview of position analysis and dimensional synthesis for kinematics of machines. It discusses topics such as position and displacement, dimensional synthesis, function generation, path generation, motion generation, limiting conditions like toggle positions and transmission angles, and both graphical and algebraic methods for position analysis including vector loops and the use of complex numbers. The key steps of graphical position analysis and the algebraic algorithm using Freudenstein's equation are described.
This document presents two numerical methods for evaluating integrals involving the linear-shape function times the 3D Green's function on a plane triangle. The conventional method splits the integral into an analytical and numerical part, while the alternative method proposed evaluates the integral fully numerically. Numerical results show the alternative method is conceptually simpler, easier to implement, and achieves similar or better accuracy compared to the conventional method.
This chapter discusses elastic and viscoplastic self-consistent theories for predicting the effective mechanical behavior of polycrystalline materials from their microstructure. It reviews how crystal elasticity and plasticity theories can be used in mean-field homogenization methods like the self-consistent approximation. Examples are given of applying the elastic self-consistent method to predict effective properties of composites and textured polycrystals. The viscoplastic self-consistent method is also described for modeling the rate-dependent behavior of polycrystals based on linearizing the nonlinear viscoplastic behavior at the grain scale.
Investigation of interfacial properties at quartz alkane interfaces using mol...IAEME Publication
The document discusses a molecular dynamics simulation investigating the interfacial properties of α-quartz/alkane interfaces. Specifically, it examines the density and orientation order parameter of decane and tetracosane molecules near hydroxyl-terminated and hydrogen-terminated α-quartz (100) surfaces at various temperatures. The simulation models the α-quartz using the Lopes force field and models the alkanes using the NERD united atom force field. Results show that adsorption of alkane molecules is more pronounced at lower temperatures. Orientation of molecules near the hydrophilic surface is more parallel to the interface than those near the hydrophobic surface. Density profiles reveal oscillating densities near the interface with higher peaks indicating more ordering.
A METHODOLOGY FOR ANALYSIS OF TOPOLOGICAL CHARATERISTICS OF PLANETARY GEAR TR...meijjournal
A planetary trains for multi-speed is mainly used for automation in industries of automobile. A planetary
gear train is represented by a graph. It is identified by (i) number of vertices and their connectivity (ii)
number of edges and their types and values (iii) fundamental circuits, their size and adjancy. Connectivity
of individual link is a property characteristic of kinematic chain. It is possible to identify a planetary gear,
therefore of using sets of labele (decimal numbers representing connectivity ) of individual link. The
connectivity of vertices , edges values and circuit values, related to design invariants which in turn
indicates the possible behavior of the gear train ( for example capacity of power transmission, speed ratio
and power carculation). For a specified degree – of – freedom a number of planetary gear kinematic chain
(PGKCs) are selected and hence planetary gear trains (PGTs) can be formed with a given number of links
and joints so that designer must be able to select to select the best train from the view point of say velocity
ratio and capacity of power transmission, space requirements etc. Synthesis of planetary gear kinematic
chain and planetary gear trains has been studied(1-9). Almost all reported work deals with only
identification of distinct chains. Besides providing an atlus of chains, this in itself does not provide any help
to designer in the selection of best possible gear train. In the present paper a simple method based of
circuit property ( based on link-link shortest path distance and degree of links) is presented to determine
the topology values of power transmission efficiency and topology power transmission capacity of five-links
PGKCs and their distinct inversions.
A METHODOLOGY FOR ANALYSIS OF TOPOLOGICAL CHARATERISTICS OF PLANETARY GEAR TR...
Gf3111931199
1. Ruby Mishra, T.K.Naskar, Sanjib Acharya / International Journal of Engineering Research
and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 3, Issue 1, January -February 2013, pp.1193-1199
Synthesis of coupler curve of a Four Bar Linkage with joint
Clearances
Ruby Mishra*, T.K.Naskar** and Sanjib Acharya**
*
School of Mechanical Engineering, KIIT University, BBSR- 751024, India
**
Mechanical Engineering Departments, Jadavpur University, Kolkata-700032, India
Abstract
In this paper, synthesis of linkages with modeled like a small link with length equals to one
joint clearances to generate a desired coupler half of the clearance. A geometrical model was used
curve is studied. These clearances are treated as in their method to assess the output position or
a mass less link and the equation of its motion direction variation, to predict the limit of position
were found by using Lagrange’s equation. uncertainty and to determine the maximum
Dynamic parameters are used in Lagrange’s clearance. Mallik and Dhande [7] introduced a
equation to define the direction of motion of stochastic model of the four-bar, path-generating
clearance. Deferential evaluation (DE) method linkage with tolerance and clearance to analyze the
was used to analyze the optimization of link mechanical error in the path of a coupler point.
parameters for minimizing the error between Tolerances and clearances were assumed to be
desired and actual path due to clearances at joint random variables. Schwab et al [8] studied dynamic
of coupler and follower. . response of mechanisms and machines affected by
clearance in revolute joint and a comparison was
Key words: path synthesis, joint clearances, made between several continuous contact force
Lagrange’s equation, Differential evaluation (DE), models and an impact model. Tsai and Lai [9]
optimization. performed position analysis of a planar 4-bar
mechanism with joint clearance by using loop-
1. INTODUCTION closure equations. Clearance was treated as a virtual
Joint clearance is a important factor that link in this work. Flores and Ambrosio et al [10]
affect the dynamic stability and the performance of performed dynamic analysis of mechanical systems
mechanical system. It is generally exist in all kinds considering realistic joint characteristics like joints
of planar mechanism. Clearance can causes with clearance and lubrication. The work analyzed
vibration and noise and also affect the dynamic contact impact forces of the kinematics and dynamic
properties of the machine. So clearance may play a system. The joint clearance was modeled as a
important role to define the kinematic and dynamic contact pair with dry contact as well as lubrication.
behavior of mechanisms. Without considering For the lubricated case, the theory of hydrodynamic
clearance we assume the linkage is called rigid link journal–bearings was used to compute the forces
and when clearance is assumed in joints, the generated by lubrication action. Tsai and Lai [11]
resulting linkage is called flexible linkage. A no. of used equivalent kinematical pair in multi-loop
works is reported in journals on flexible linkages linkage to model the motion freedoms obtained from
and modeling of joint clearance. joint clearances. The clearances were considered to
The initial framework for the study of be virtual links. Erkaya and Uzmay [12] studied the
planar flexible link mechanisms has been provided effects of joint clearance on quality of path
by Boronkay and Mei [1] analyzed linkages whose generation and transmission angle. In the paper GA
pivots were replaced by flexible joints. Dubowsky approach was used to determine the direction of
[2] investigated the effects of joint clearance in a joint clearance relative to input link of a 4-bar
slider crank mechanism considering impact model. linkage.
Burns and Crossley [3] in their investigation of the In this paper, the nonlinear behavior in a
structural permutations of flexible link 4-bar chains four bar mechanism with joint clearance at the
having revolute pairs. This led to the development coupler and follower and its effect on path
of techniques for the dimensional synthesis of generation is analyzed. Differential evaluation
devices that satisfied specific motion requirements method using langrage’s equation is applied to
by undergoing large elastic deformations. T. describe the direction of joint clearances. And also
Furuhashi, N. Morita and M. Matsuura [4-5] using this method an objective function is defined
determined angular directions of joint clearances by and parametric relations between input variable and
assuming continuous contact in revolute joints with direction of joint clearances are considered as the
clearance and using Lagrange function. Ting et al constraints for solving nonlinear differential
[6] presented an approach to identify the position equation .Using DE optimization of the mechanism
and direction errors due to the joint clearance of link parameters is also performed to minimize the
linkages and manipulators. Joint clearance was
1193 | P a g e
2. Ruby Mishra, T.K.Naskar, Sanjib Acharya / International Journal of Engineering Research
and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 3, Issue 1, January -February 2013, pp.1193-1199
path errors between desired and actual mechanisms
is analyzed.
2. Modeling of Joint clearance
It is assumed that links of mechanism are
connected to each other by revolute joints with
clearance. Joint clearance, shown in Fig 1.Joint
clearance r2 is defined as the difference between the
radii of the pin and hole, rB and rJ respectively.
When the journal gives impact on the bearing wall, Fig. 3 .vector representation of mechanism
normal and tangential force occurs. Also, if the
friction is negligible, the direction of joint clearance From the close loop vector relation
vector coincides with the direction of normal force
L1e i1 L2 e i 2 L3 e i3 L4 e i 4 r2 e i 2 r3 e i 3 0
c c
at the contact point. When the continuous contact ( 2)
mode between journal and bearing at joint is
considered, the clearance may be modeled as vector By separating Eq. (2), into its real part and
which corresponds to mass less virtual link with the imaginary part and using trigonometric relations,
length equal to joint clearance. 3c and 4 with joint clearance can be expressed
c
The equivalent clearance (clearance vector) can be
defined in the form as a function of 2 and 2 respectively:
r2 rB rJ (1) 3c 2 tan1
B B2 4 AC
( 3)
2A
r2 rB L L cos 2 r2 cos 2 L3 cos 3c r3 cos 3
4c cos1 1 2 ...(4)
j link
L4
i link rJ Where the superscript c denotes the value with
clearance. A, B, C terms are given, with joint
Fig.1. Equivalent clearance link clearance respectively .
3. Synthesis of four bar path generator with A L1 L3 2 L2 cos 2 2r2 cos 2 2r3 cos 3
joint clearance. 2 L2 r2 cos 2 2 2 L2 r3 cos 2 3 2r2 r3 cos 2 3 ...(5)
Dimensional synthesis of 4-bar linkage for path
2 L1 L3 L1 L2 L3 L4 r2 r3
2 2 2 2 2 2
generation involves
A) The determination of the dimension of the
linkage related to the desired path B 4L3 L2 sin 2 r2 sin 2 r sin 3 ...(6)
3
B) The minimization of structural error which
is subject to a set of size and geometric C L3 L1 2 L2 cos 2 2r2 cos 2 2r3 cos 3
constant. 2 L2r2 cos 2 2 2 L2 r3 cos 2 3 2r2r3 cos 2 3 2 L1L3 (7)
3.1. 4-Bar mechanism with double clearance
L1 L2 L3 L4 r2 r3
2 2 2 2 2 2
A four-bar mechanism with double
clearance, as shown in Fig (2), is considered as an
example to determine the effect of joint clearance As shown in Fig.2, the position of the coupler point
between crank and coupler on path generation. P x, y relative to the crank pivot A1 is given with
Kinematic equations are derived from the vector joint clearance, respectively:
configuration of the mechanism, shown in Fig (3) Pxc L2 cos 2 r2 cos 2 AP cos 3
c
(8)
Py L2 sin 2 r2 sin 2 AP sin 3 . (9)
c c
c
Where Px , Pyc denote the X andY coordinate values
for the path of the coupler point in considering the
joint clearance.
In the kinematic analysis of the 4-bar
mechanism with double joint clearance, it is
Fig.2. Schematic representation of a 4-bar necessary to determine the position of mass centre
mechanism with clearance for moving links and then their corresponding
velocities and accelerations. So in the case of joint
1194 | P a g e
3. Ruby Mishra, T.K.Naskar, Sanjib Acharya / International Journal of Engineering Research
and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 3, Issue 1, January -February 2013, pp.1193-1199
clearance these positions are derived from the vector These differential equations determine the motion
representation of the mechanism in Fig.3. of the system. Similarly we can determine the
Due to motion transmission from crank direction of 3 . They are used to determine the
link to follower, joint clearance between crank and direction of the joint clearance with respect to input
coupler has important role on the path generation by
and are solved by DE on MATLAB software.
coupler point P . If the crank pivot A1 is taken as
the reference point, the mass centre positions for 5. Case study
moving links are given as follows. A case study is conducted four bar linkage
xG 2 A G2 cos 2
c
0 (10) with clearances in the revolute joint connecting the
input link and the coupler. Values of dynamic
yG 2 A G2 sin 2
c
(11) parameters used in Lagrange’s equation are given in
0
c
xG3
L2 cos 2 r2 cos 2 AG3 cos c
3 (12)
Table 1.
c
yG 3 L2 sin 2 r2 sin 2 AG3 sin c
3 (13) Table .1. Assumed values of dynamic parameters
xG 4 L2 cos 2 r2 cos 2 L3 cos 3c r3 cos 3 BG4 cos 3c (14)
c
Descriptions parameters values
MOI of the link 2 I2 5.12 104 Kg m2
yG 4 L2 sin 2 r2 sin 2 L3 sin 3 r3 sin 3 BG4 sin 3
c c c
(15)
MOI of the link 3 I3 8.85103 Kg m2
4. Lagrange’s equation MOI of the link 4 I4 1.58103 Kg m2
The Lagrange’s equation is used to determine 2 , Mass of the link2 m2 0.121Kg
3 the direction of the mass less clearance link. Mass of the link 3 m3 1.048Kg
For this specific purpose the equation can be Mass of the link 4 m4 0.071Kg
expressed as Gravitational g 9.8 m / s 2
acceleration
d
K .E K .E P.E D.F 0 (16)
Input angular 2 62.83 rad / s
dt 2 2 2 2 velocity
Damping C i 0.2 106 Kgm s / rad
coefficient
Where, the kinetic energy ( K.E. ), potential energy
( P.E. ) and dissipation function ( D.F. ) are: Damping C 2 , C 3 0.2 106 Kgm s / rad
coefficient
K .E.
1 4
2 i 2
I i ic
2
1 4
mi xGi
2 i 2
c y 2
2
c
Gi
6. DE to determine direction of joint
4
P.E. mi gyGi
c
(17) clearance
i 2 The equation of motion of the system has a
non linear character as it is obvious from Eq. (18).
1 4 2 1
D.F
C i ic C 2
2
2 i 2 2 2 The direction of the clearance link 2 and 3 is
determined as a function of the direction of the input
The Eqs. (17) together with Eq. (16) give, link by optimization approach using DE. The
4 c ic c x c y c y c c objective function is expressed as [12],
I ii
mi Gi Gi Gi Gi
x yc gmi Gi Ciic i C 2 2 0
(18)
2 2 2 2 4
x c y c y c c
i 2
c
2 MinimizeFx f I iic i mi Gi Gi Gi Gi gmi Gi Ci ic i C 2 2 ,
xc yc
i 2
2 2 2 2 2
h j x 0, xl x j xu , x j X , (19)
4
x c y c y c c
c
MinimizeFx f I iic i mi Gi Gi Gi Gi gmi Gi Ciic i C 3 3 ,
xc yc
i 2
3 3 3 3 3
h j x 0, xl x j xu , x j X , (20)
Where h j ( x ) are the equality constraints
that depend on parametric relations between
direction of clearance link and input variable; X is a
vector that comprises the design variables
corresponding to direction of clearance link, that is,
1195 | P a g e
4. Ruby Mishra, T.K.Naskar, Sanjib Acharya / International Journal of Engineering Research
and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 3, Issue 1, January -February 2013, pp.1193-1199
2 , 2 and xl and xu are the lower and upper 7. Result considering different values of joint
bounds of the design variables, respectively. clearance.
The objective function is the sum of two
terms. The first part computes the position error
(also called the structural error) as the sum of
squares of the Euclidian distances between each
desired points along the coupler curve ( Px , Py ) that d
i
d
i
has to be traced by the mechanism and the
corresponding generated points ( Px , Py ) by the g
i
g
i
designed mechanism. The desired points are a set of
target points along the coupler curve indicated by
the designer and should be met by the coupler point
of the mechanism and the generated curve is the
curve that is actually obtained by the coupler point
of the designed mechanism. For minimizing the
error between desired and generated curves, the
objective function is given by
Fig 4. Coupler curve for r 2=1 mm and r 3=1 mm
N
Pyg
1 i 2
Minim ize F ( x) i
Pxd Pxg 2
i i
Pyd
N
i 1
subject to h j x 0, xl x j xu , (21)
where N num berof precision point s
The inequality constraints h j x consist of
conditions of Grashof’s rule that specifies crank
rocker situation. xl and xu are respectively the lower
and upper bounds of the design variables. They
consist of link lengths Li , ( Pxd i , Py d i ) and the
structural angle, the angle that the line AP
makes
AB
with the line of centre of the coupler as seen in
to obtain the co-ordinates of the generated
Fig. 2
positions of the coupler point displacement analysis Fig .5. Coupler curve for r 2=1 mm and r3=2 mm
is essential.
The successful application of the developed
methodology for synthesis of mechanisms is shown
through some case studies. All the data presented
here are in a consistent set of units, i.e., all linear
dimensions are in the unit of length and the angular
dimensions are in degrees unless otherwise stated.
For each case study an intermediate result and the
final result are given. Finally, a summary of the
results of all the cases indicating the values of the
design variables obtained through DE is presented.
The optimization algorithm is applied using
MATLAB version 7.1. All the linkages shown in the
following sections are obtained by using the design
variables. Here the technique of geometric centroid
of precision points (GCPP) [12] has been used to
define the initial bounds of the design variables. The
GCPP is obtained by evaluating the mean Fig.6. Coupler curve for r 2=2 mm and r 3=1 mm
coordinates X cg and Ycg (mass center position) of
the desired precision points in X and Y directions
respectively.
1196 | P a g e
5. Ruby Mishra, T.K.Naskar, Sanjib Acharya / International Journal of Engineering Research
and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 3, Issue 1, January -February 2013, pp.1193-1199
Fig.10 (θ2) for r2=2 mm and r3=1 mm
Fig.7. Coupler curve for r 2=2 mm and r3=2 mm
Figs. (8-11) Direction of joint clearance with
respect to position of input link (θ2)
Fig.11. for r2=2 mm and r 3=2 mm
Figs. (12-15) Path error between desired and actual
mechanism and path error between desired and
optimised mechanism.
Fig.8. for r2=1 mm and r3=1 mm
Fig.12 for r2=1 mm and r3=1 mm
Fig.9 for r2=1 mm and r3=2 mm
Fig.13 for r2=1 mm and r3=2 mm
1197 | P a g e
6. Ruby Mishra, T.K.Naskar, Sanjib Acharya / International Journal of Engineering Research
and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 3, Issue 1, January -February 2013, pp.1193-1199
8. Conclusion
In this study, for determining the effect of
joint clearance on coupler curves the joints with
clearance at the contact point of crank and coupler
and contact point of coupler and follower have
considered. Here the optimum link lengths are found
out with an objective to minimize the error in the
path generation considering the given joint
clearances. It is observed from the result that after
doing optimization we can reduce the error between
the desired and optimized curve. These results can
be seen as appropriate optimization technique for
minimizing the actual error in the presence of
Fig.14. for r 2=2 mm and r3=1 mm clearances. The values of the clearances may vary
due to precision to be maintained. Therefore
optimum results are extracted for different set of
values of the clearances to study the effect of joint
clearances on the minimized error.
From the result it can be adapted to similar systems
to improve the mechanical working conditions.
References
[1] R.H. Burns and F.R.E. Crossley, Structural
Permutations of Flexible Link
Mechanisms, ASME Paper, 66-Mech-5.
[2] T. G. Boronkay and C. Mei, Analysis and
Design of Multiple Input Flexible Link
Fig.15 for r 2=2 mm and r 3=2 mm Mechanisms, Journal of Mechanisms 5
(1970), pp.29-40.
7.1. Optimized design variables for different values [3] S. Dubowsky, On predicting the dynamic
of joint clearance effect of clearances in planar mechanisms,
The minimized error between desired curve ASME Journal of Engineering for industry
and generated curve are shown in table 2 for 93B (1974) (1) pp. 317-323.
different clearance value. [4] T. Furuhashi, N. Morita and M. Matsuura,
Research on dynamics of four-bar linkage
Table 2 .Optimized design variables for different with clearances at turning pairs (1st Report,
values of joint clearance General theory of continuous contact
model), Bulletin of the JSME 21 (1978),
First 1 mm 1 mm 2 mm 2 mm pp. 518–523.
clearance [5] N. Morita, T. Furuhashi and M. Matsuura,
Second 1 mm 2 mm 1 mm 2 mm Research on dynamics of four-bar linkage
clearance with clearances at turning pairs (2nd
L1 (mm) Report, Analysis of crank-level mechanism
400.0481 399.8386 400.2295 401.1023 with clearance at joint of crank and coupler
using continuous contact model), Bulletin
L2 (mm)
of the JSME 21 (1978), pp. 1284–1291.
100.0600 99.9970 100.1718 100.0828
[6] A.K. Mallik and S.G. Dhande, Analysis
L3 (mm)
and synthesis of mechanical error in path-
361.9587 359.2392 360.2949 365.5831
generating linkages using a stochastic
L4 (mm)
approach, Mechanism and Machine Theory
249.2171 239.2488 247.5518 259.4261 22 (1987), pp. 115-123.
A'P (mm) [7] K.W. Ting, J. Zhu and D. Watkins, The
304.1872 304.2217 303.3092 303.3529 effects of joint clearance on position and
β (degree) orientation deviation of linkages and
18.7884 20.1741 19.1220 17.2177 manipulators, Mechanism and Machine
Error Theory 35 (2000), pp. 391–401.
(normalized) [8] A.L. Schwab, J.P. Meijaard and P. Meijers,
(mm) 0.369 0.332 0.635 0.700 A comparison of revolute joint clearance
models in the dynamic analysis of rigid and
1198 | P a g e
7. Ruby Mishra, T.K.Naskar, Sanjib Acharya / International Journal of Engineering Research
and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 3, Issue 1, January -February 2013, pp.1193-1199
elastic mechanical systems, Mechanism
and Machine Theory 37 (2002) 895–913.
[9] M.J. Tsai and T.H. Lai, Kinematic
sensitivity analysis of linkage with joint
clearance based on transmission quality,
Mechanism and Machine Theory 39
(2004), pp. 1189–1206.
[10] P. Flores, J. Ambrosio, J.C.P. Claro, H.M.
Lankarani and C.S. Koshy, A study on
dynamics of mechanical systems including
joints with clearance and lubrication,
Mechanism and Machine Theory 41
(2006), pp. 247–261.
[11] M.J. Tsai and T.H. Lai, Accuracy analysis
of a multi-loop linkage with joint
clearances, Mechanism and Machine
Theory 43 (2008) 1141–1157.
[12] S. Erkaya and I. Uzmay, Determining link
parameters using genetic algorithm in
mechanisms with joint clearance,
Mechanism and Machine Theory 44 (2009)
222–234.
1199 | P a g e