On the Kinematics and Kinetics of Mechanical Seals, Rotors, and Wobbling Bodies

2005 ◽  
Author(s):  
Itzhak Green
Keyword(s):  
Equations Of Motion ◽  
Mechanical Seals ◽  
Kinematical Constraint ◽  
Lagrange’S Equations ◽  
Dynamic Analyses ◽  
Kinematical Model ◽  
Kinetics Of ◽  
Kinematics And Kinetics ◽  
Lagrange's Equations

Mechanical seals, rotors, and wobbling bodies are characterized by a kinematical constraint that prevents them from having integral motion with respect to their own frame. A valid kinematical model is a prerequisite to subsequent dynamic analyses. Three previous works have suggested distinctly different kinematical models to the same problem. The analysis herein presents yet another kinematical model that preserves (actually enforces) the proper kinematical constraint. The outcome reaffirms one of the previous models. The equations of motion are derived using Lagrange’s equations to complement results obtained previously by Newton-Euler mechanics.

Experimental Analysis of a Planar Reconfigurable Mechanism With a Variable Joint

2016 ◽  
Author(s):  
Peter W. Malak ◽  
Anthony J. Buchta ◽  
Philip A. Voglewede
Keyword(s):  
Optimal Control ◽  
Transition Point ◽  
Physical Mechanism ◽  
Equations Of Motion ◽  
Angular Position ◽  
The Other ◽  
Simplified Model ◽  
Physical Prototype ◽  
Kinetics Of ◽  
Kinematics And Kinetics

Previously a specific planar reconfigurable mechanism with a variable joint (RRRR1 -RRRP2 Mechanism) was dynamically modeled. The RRRR-RRRP Mechanism functions as a RRRR mechanism in one configuration and as a in RRRP mechanism the other. The kinematics and kinetics of the RRRP and RRRR configurations were previously analyzed with a Lagrangian approach. The developed equations of motion will be validated with a physical prototype in this paper. In addition, a simplified model of the RRRR-RRRP Mechanism is also developed and compared to the experimental results. The experimental angular position of each joint on the RRRR-RRRP Mechanism will be compared to the model position analysis. Particular attention will be given to the transition point when the physical mechanism changes from an RRRR mechanism to RRRP mechanism and vice versa as it is vital to knowing this point for optimal control of the mechanism.

scholarly journals Proof of Lagrange's Equations of Motion, &c.

Nature ◽  
1903 ◽  
Vol 67 (1740) ◽  
pp. 415-415
Author(s):  
W. MCF. ORR
Keyword(s):  
Equations Of Motion ◽  
Lagrange’S Equations ◽  
Lagrange's Equations

scholarly journals Proof of Lagrange's Equations of Motion, &c.

Nature ◽  
1903 ◽  
Vol 67 (1740) ◽  
pp. 415-415
Author(s):  
R. F. W.
Keyword(s):  
Equations Of Motion ◽  
Lagrange’S Equations ◽  
Lagrange's Equations

scholarly journals Finite Element Method-Based Elastic Analysis of Multibody Systems. A Review

Mathematics ◽  
2022 ◽  
Vol 10 (2) ◽  
pp. 257
Author(s):  
Sorin Vlase ◽  
Marin Marin ◽  
Negrean Iuliu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Mechanical System ◽  
Multibody Systems ◽  
Equations Of Motion ◽  
Alternative Methods ◽  
Engineering Applications ◽  
Lagrange’S Equations ◽  
Lagrange's Equations ◽  
Element Method

This paper presents the main analytical methods, in the context of current developments in the study of complex multibody systems, to obtain evolution equations for a multibody system with deformable elements. The method used for analysis is the finite element method. To write the equations of motion, the most used methods are presented, namely the Lagrange equations method, the Gibbs–Appell equations, Maggi’s formalism and Hamilton’s equations. While the method of Lagrange’s equations is well documented, other methods have only begun to show their potential in recent times, when complex technical applications have revealed some of their advantages. This paper aims to present, in parallel, all these methods, which are more often used together with some of their engineering applications. The main advantages and disadvantages are comparatively presented. For a mechanical system that has certain peculiarities, it is possible that the alternative methods offered by analytical mechanics such as Lagrange’s equations have some advantages. These advantages can lead to computer time savings for concrete engineering applications. All these methods are alternative ways to obtain the equations of motion and response time of the studied systems. The difference between them consists only in the way of describing the systems and the application of the fundamental theorems of mechanics. However, this difference can be used to save time in modeling and analyzing systems, which is important in designing current engineering complex systems. The specifics of the analyzed mechanical system can guide us to use one of the methods presented in order to benefit from the advantages offered.

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