scholarly journals Friction Forces in Numerical Simulations of Kinematical Joints of Mechanical Systems

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.

The Stick Motion of a Harmonically Excited, Friction-Induced Oscillator on a Sinusoidally Traveling Surface

2006 ◽  
Author(s):  
Albert C. J. Luo ◽  
Brandon C. Gegg ◽  
Steve S. Suh
Keyword(s):  
Dynamical Systems ◽  
Numerical Simulations ◽  
Dry Friction ◽  
The Other ◽  
Linear Oscillator ◽  
Analytical Prediction ◽  
Nonlinear Friction ◽  
Friction Forces

In this paper, the methodology is presented through investigation of a periodically, forced linear oscillator with dry friction, resting on a traveling surface varying with time. The switching conditions for stick motions in non-smooth dynamical systems are obtained. From defined generic mappings, the corresponding criteria for the stick motions are presented through the force product conditions. The analytical prediction of the onset and vanishing of the stick motions is illustrated. Finally, numerical simulations of stick motions are carried out to verify the analytical prediction. The achieved force criteria can be applied to the other dynamical systems with nonlinear friction forces possessing a CO - discontinuity.

Analysis of Motion of the Impact-Dry-Friction Pair of Bodies and its Application to the Investigation of the Impact Dampers Dynamics

1999 ◽  
Author(s):  
František Peterka
Keyword(s):  
Analytical Solution ◽  
Numerical Simulations ◽  
Mechanical System ◽  
Relative Motion ◽  
Dry Friction ◽  
Friction Pair ◽  
Strong Nonlinearity ◽  
Friction Forces ◽  
The Impact ◽  
Analysis Of Motion

Abstract The motion with impacts and dry friction forces appears in some mechanical systems as mechanisms with clearances, (e.g., in gearings, pins, slots, guides, valve gears etc.), impact dampers, relays, forming and mailing machines, power pics etc. Such mechanisms include one or more pairs of impacting bodies, which introduce the strong nonlinearity into the system motion. The motion of the general pair of bodies with the both-sides impacts and dry friction forces is assumed (Fig.1). It can be the part of a more complex chain of masses in the mechanical system. Dead zones in the relative motion of bodies can be caused by assumed nonlinearities. The mathematical conditions controlling the numerical simulations or analytical solution of the motion are introduced. The application of this method is explained by the study of the influence of dry friction force on amplitude-frequency characteristics of four types of dynamical and impact dampers with optimised parameters.

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

2015 ◽  
Vol 80 (1-2) ◽  
pp. 309-328 ◽  
Author(s):  
Shaoze Yan ◽  
Wuweikai Xiang ◽  
Lin Zhang
Keyword(s):  
Mechanical Systems ◽  
Comprehensive Model ◽  
Revolute Joints

Two-Dimensional Linear Friction Damper Consisting of Concave Cone and Cylindrical Member (Investigation of Performance by Numerical Simulation and Experiment)

2015 ◽  
Author(s):  
Hideya Yamaguchi ◽  
Hidehisa Yoshida
Keyword(s):  
Numerical Simulations ◽  
Friction Force ◽  
Vibration Isolation ◽  
Two Dimensions ◽  
Resonant Peak ◽  
Friction Damper ◽  
Isolation System ◽  
Friction Forces ◽  
Vibration Isolation System ◽  
Linear Friction

A passive vibration isolation system consisting of a constant friction force has performance limitations; the isolation performance declines and the residual displacement becomes large in the case of the large friction force, while the resonant peak becomes large in the case of the small friction force. It is known that above drawbacks are avoidable when the friction force varies in proportion to the relative displacement. Recently, authors have proposed a simple linear friction damper mechanism that consists of a cylindrical block and a tilt lever supported with a pivot or a leaf spring. Performance of the vibration isolation system equipped with the proposed damper is investigated, and its effectiveness is confirmed by numerical simulations and the experiments. However, the motion of the mechanism is limited to one-dimension. This paper proposes an extended mechanism that can be applied to motion moving in two dimensions by combining the concave cone and the cylindrical member. The concave cone is supported with a universal joint on the apex side and its tilting motion is constrained by the restoring spring. The rounded edge of the cylindrical member is set up to contact the inside flank of the concave cone. When the cylindrical member moves in an arbitrary direction on the planar floor and pushes the concave cone, the normal and friction forces at the contact point vary depending on the displacement of the cylindrical member. The fundamental property and the performance of the proposed mechanism are investigated by numerical simulations and experiments.

Dexterous Workspace of n-PRRR Planar Parallel Manipulators

2012 ◽  
Vol 4 (3) ◽  
Author(s):  
André Gallant ◽  
Roger Boudreau ◽  
Marise Gallant
Keyword(s):  
Kinematic Chain ◽  
Parallel Manipulators ◽  
Divergence Theorem ◽  
End Effector ◽  
Kinematic Chains ◽  
Prismatic Joint ◽  
Planar Surfaces ◽  
Revolute Joints ◽  
Gauss Divergence Theorem ◽  
Planar Parallel Manipulators

In this work, a method is presented to geometrically determine the dexterous workspace boundary of kinematically redundant n-PRRR (n-PRRR indicates that the manipulator consists of n serial kinematic chains that connect the base to the end-effector. Each chain is composed of two actuated (therefore underlined) joints and two passive revolute joints. P indicates a prismatic joint while R indicates a revolute joint.) planar parallel manipulators. The dexterous workspace of each nonredundant RRR kinematic chain is first determined using a four-bar mechanism analogy. The effect of the prismatic actuator is then considered to yield the workspace of each PRRR kinematic chain. The intersection of the dexterous workspaces of all the kinematic chains is then obtained to determine the dexterous workspace of the planar n-PRRR manipulator. The Gauss divergence theorem applied to planar surfaces is implemented to compute the total dexterous workspace area. Finally, two examples are shown to demonstrate applications of the method.

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

2011 ◽  
Vol 7 (1) ◽  
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.

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

2012 ◽  
Vol 134 (2) ◽  
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.

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

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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