Interface reduction methods for mechanical systems with elastohydrodynamic lubricated revolute joints

The component mode synthesis based on the Craig-Bampton method has two strong limitations that appear when the number of the interface degrees of freedom is large. First, the reduced-order model obtained is overweighed by many unnecessary degrees of freedom. Second, the reduction step may become extremely time consuming. Several interface reduction techniques addressed successfully the former problem, while the latter remains open. In this paper we tackle this latter problem through a simple interface-reduction technique based on an a-priory choice of the interface modes. An efficient representation of the interface displacement field is achieved adopting a set of orthogonal basis functions determined by the interface geometry. The proposed method is compared with other existing interface reduction methods on a case study regarding a rotor blade of an axial compressor.

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Electrical Elements in Reduction of Mechanical Vibrations

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.371.657 ◽

2013 ◽

Vol 371 ◽

pp. 657-661 ◽

Cited By ~ 9

Author(s):

Katarzyna Białas

Keyword(s):

Mechanical System ◽

Vibration Reduction ◽

Mechanical Systems ◽

Synthetic Method ◽

Basic System ◽

Mechanical Vibrations ◽

Parametric Synthesis ◽

System Designer ◽

Active Elements ◽

Reduction Methods

This work presents methods of reduction of the vibration of mechanical systems by means of active elements as well as examples of implementation of active reduction of vibration by means of electrical elements [. This work also describes a structural and parametric synthesis, which can be defined as the design of systems meeting specific requirements. These requirements refer to the frequency values of the systems vibration. The presented approach i.e. a non-classical synthetic method applied in designing mechanical systems, one (as early as at the design and construction stage) may verify future systems [1-. This work presents the description of vibration reduction methods. The most popular methods are passive, active and semi-active. An important aspect of this work is the presentation of several possibilities of the physical implementation of active subsystems. In examples active subsystems consisted of the following electric elements is coil with a movable core. In this work is presents influence of electrical subsystem to basic mechanical system. Designer should analyse the resultant systems and investigate the interaction between the subsystems and the basic system [4-.

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A comprehensive model for 3D revolute joints with clearances in mechanical systems

Nonlinear Dynamics ◽

10.1007/s11071-014-1870-7 ◽

2015 ◽

Vol 80 (1-2) ◽

pp. 309-328 ◽

Cited By ~ 34

Author(s):

Shaoze Yan ◽

Wuweikai Xiang ◽

Lin Zhang

Keyword(s):

Mechanical Systems ◽

Comprehensive Model ◽

Revolute Joints

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Friction Forces in Numerical Simulations of Kinematical Joints of Mechanical Systems

Robotica & Management ◽

10.24193/rm.2021.1.2 ◽

2021 ◽

Vol 26 (1) ◽

pp. 9-12

Author(s):

Calin-Octavian Miclosina ◽

Vasile Cojocaru ◽

Daniel-Gheorghe Vela

Keyword(s):

Numerical Simulations ◽

Mechanical Systems ◽

Friction Forces ◽

Simulation Process ◽

Planar Surfaces ◽

Revolute Joints

The paper presents a way of estimation, by simulation, of friction forces that occur in the kinematical joints of mechanical systems. Friction forces between planar surfaces, in revolute joints, and in spherical joints are computed, and the results are compared with the values achieved from simulation. SolidWorks software is used for the simulation process.

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STUDY AND COMPARISON OF REDUCTION METHODS OF MECHANICAL SYSTEMS.

10.20906/cps/cob-2015-2396 ◽

2015 ◽

Author(s):

Daniel Ferreira Gonçalves ◽

Lázaro Antônio da Fonseca Júnior ◽

Romes Antônio Borges ◽

Antônio Marcos Gonçalves de Lima

Keyword(s):

Mechanical Systems ◽

Reduction Methods

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Analysis of the Dynamic Behavioral Performance of Mechanical Systems With Multi–Clearance Joints

Journal of Computational and Nonlinear Dynamics ◽

10.1115/1.4004263 ◽

2011 ◽

Vol 7 (1) ◽

Cited By ~ 42

Author(s):

S.M. Megahed ◽

A.F. Haroun

Keyword(s):

Impact Force ◽

Dynamic Performance ◽

Mechanical Systems ◽

Behavioral Performance ◽

Clearance Joints ◽

Revolute Joints ◽

Clearance Joint ◽

Computation Algorithm ◽

Maximum Impact Force ◽

Crank Mechanism

In this investigation, the effect of revolute joints’ clearance on the dynamic performance of mechanical systems is reported. A computation algorithm is developed with the aid of SolidWorks/CosmosMotion software package. A slider-crank mechanism with one and two clearance-joints is studied and analyzed when working in vertical and in horizontal planes. The simulation results point out that the presence of such clearance in the joints of the system understudy leads to high peaks in the characteristic curves of its kinematic and dynamic performance. For a multiclearance joints mechanism, the maximum impact force at its joints takes its highest value at the nearest joint to the input link. This study also shows that, when the mechanism works in horizontal plane, the rate of impacts at each clearance-joint increases and consequently the clearance-joints and actuators will deteriorate faster.

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Influence of Contact Geometry on Local Friction Energy and Stiffness of Revolute Joints

Journal of Tribology ◽

10.1115/1.4006248 ◽

2012 ◽

Vol 134 (2) ◽

Cited By ~ 18

Author(s):

Alexander Gummer ◽

Bernd Sauer

Keyword(s):

Dynamic Behavior ◽

Contact Zone ◽

Mechanical Systems ◽

Contact Geometry ◽

Rotational Degree ◽

Multibody Simulation ◽

Calculation Algorithm ◽

Robotic Arms ◽

Revolute Joints ◽

Friction Energy

Revolute joints (also called pin joints or hinge joints) are used in many different mechanical systems such as robotic arms, door hinges, folding mechanisms, or hydraulic shovels. Since they transmit forces and give a rotational degree of freedom to the connected parts, revolute joints have a major impact on the dynamic behavior of the system into which they are built. Two main characteristics of these elements are their stiffness and their clearance. Both of them change as the wear between the joint’s pin and the rod hole increases during operation. In order to consider these aspects in a multibody simulation an analytical, numerically effective method has been developed to calculate the stiffness of a revolute joint in dependence of the geometry and the wear state. In addition, the calculation algorithm allows for for the analysis of the local friction energy that occurs in the contact zone. In this paper, the calculation approach is presented together with the results for two different steady loaded revolute joints.

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An Overview of Several Formulations for Dry and Lubricated Revolute Joint Clearances in Planar Rigid-Multi-Body Mechanical Systems

Volume 6: 10th International Conference on Multibody Systems, Nonlinear Dynamics, and Control ◽

10.1115/detc2014-34399 ◽

2014 ◽

Author(s):

Paulo Flores ◽

Hamid M. Lankarani

Keyword(s):

Numerical Models ◽

Equations Of Motion ◽

Mechanical Systems ◽

Contact Forces ◽

Hertzian Contact ◽

Revolute Joint ◽

Coulomb’S Friction ◽

Revolute Joints ◽

Joint Clearances ◽

Multi Body

The influence of the revolute joint model on the dynamic response of planar multibody mechanical systems is studied in this work. In the sequel of this process, under the framework of the multibody formalisms, a general methodology for modeling the main kinematic aspects of dry revolute joint clearances is revisited. The numerical models for normal and tangential contact forces developed at the clearance joints are also discussed, which are based on the Hertzian contact theory and dry Coulomb’s friction law, respectively. The fundamental kinematic and dynamic issues of the modeling lubricated revolute joints are presented in this work in order to compare them with the dry revolute joint approach. In a simple manner, the lubrication forces are obtained by integrating the pressure distribution evaluated with the aid of Reynolds’ equation corresponding to the dynamic regime. The intra-joint forces developed for both dry and lubricated cases are evaluated based on the state of variable of the system and subsequently included into the dynamic equations of motion of the multibody system as external generalized forces. The main assumptions and procedures adopted throughout this work are demonstrated through simulations of a planar slider-crank mechanism, which includes dry and lubricated revolute joint with clearance. Finally, some experimental data is also presented and analyzed.

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