Impact Problems in Multibody Systems

2007 ◽  
pp. 193-208
Keyword(s):  
Multibody Systems ◽  
Impact Problems

scholarly journals Frictionless multiple impacts in multibody systems. I. Theoretical framework

2008 ◽  
Vol 464 (2100) ◽  
pp. 3193-3211 ◽  
Author(s):  
Caishan Liu ◽  
Zhen Zhao ◽  
Bernard Brogliato
Keyword(s):  
Multibody Systems ◽  
Contact Stiffness ◽  
Contact Point ◽  
Multiple Impacts ◽  
Contact Points ◽  
Post Impact ◽  
Relative Potential ◽  
Impact Problems ◽  
Selection Of ◽  
Theoretical Developments

A new method is proposed that can deal with multi-impact problems and produce energetically consistent and unique post-impact velocities. A distributing law related to the energy dispersion is discovered by mapping the time scale into the impulsive scale for bodies composed of rate-independent materials. It indicates that the evolution of the kinetic energy during the impacts is closely associated with the relative contact stiffness and the relative potential energy stored at the contact points. This distributing law is combined with the Darboux–Keller method of taking the normal impulse as an independent ‘time-like’ variable, which obeys a guideline for the selection of an independent normal impulse. Local energy losses are modelled with energetic coefficients of restitution at each contact point. Theoretical developments are presented in the first part in this paper. The second part is dedicated to numerical simulations where numerous and accurate results prove the validity of the approach.

Effect of Flexibility in Transverse Impact Problems

1997 ◽  
Author(s):  
Ahmet S. Yigit ◽  
Andreas P. Christoforou
Keyword(s):  
Multibody Systems ◽  
Computational Models ◽  
Functional Relationship ◽  
Impact Force ◽  
Impact Response ◽  
Flexible Body ◽  
Transverse Impact ◽  
Impact Problems ◽  
Maximum Impact Force ◽  
The Impact

Abstract The nature of impact response of a flexible body is studied. The key parameters which govern the nature of impact response are identified. The effects of these parameters on the impact response are examined through numerical simulations. It is shown that the normalized impact force and the type of impact response can be predicted through the functional relationship between the normalized maximum impact force and two nondimensional parameters termed as “loss factor” and “relative stiffness”. It is expected that the results of this study will be of great value in choosing adequate impact and computational models for the dynamic analysis of multibody systems subject to transverse impacts.

Frictional Impact Analysis in Constrained Multibody Systems

1996 ◽  
Author(s):  
Shakil Ahmed ◽  
Hamid M. Lankarani ◽  
Manual F. O. S. Pereira
Keyword(s):  
Impact Velocity ◽  
Canonical Form ◽  
Multibody Systems ◽  
Impact Analysis ◽  
Classical Problem ◽  
Double Pendulum ◽  
Joint Coordinates ◽  
Impact Problems ◽  
Energy Gains ◽  
The Impact

Abstract Analysis of impact problem in the presence of any tangential component of impact velocity requires a friction model capable of correct detection of the impact modes such as sliding, sticking, and reverse sliding. A survery of literature has shown that studies on the impact analysis of multibody systems have either been limited to the direct impact type with only a normal component of impact velocity (no frictional effect) or the ones that include friction have shown energy gains in the results due to the inherent problem in the use of Newton’s hypothesis. This paper presents a formulation for the analysis of impact problems with friction in constrained multibody mechanical systems. The formulation recognizes the correct mode of impact, i.e., sliding, sticking, and reverse sliding. The Poisson’s hypothesis is used for the definition of the coefficient of restitution, and thus the energy gains inherent with the use of Newton’s hypothesis are avoided. The formulation is developed by using a canonical form of the system equation of motion using joint coordinates and joint momenta. The use of canonical formulation is a natural way of balancing the momenta for impact problems. The joint coordinates reduces the equations of motion to a minimal set, and eliminate the complications arised from the kinematic constraint equations. The canonical form of equations are solved for the change in joint momenta using Routh’s graphical method. The velocity jumps are then calculated balancing the accumulated momenta of the system during the impact process. The impact cases are classified based on the pre-impact positions and velocities, and mass properties of the impacting systems. Analytical expressions for normal and tangential impulse are derived for each impact case. The classical problem of impact of a falling rod with the ground (a single object impact) is solved with the developed formulation, and the results are compared and verified by the solution from other studies. Another classical problem of a double pendulum striking the ground (a multibody impact) is also solved. The results obtained for the double pendulum problem confirms that the energy gain in impact analysis can be avoided by considering the correct mode of impact and using Poisson’s instead of Newton’s hypothesis.

Motion Design by Interference Analysis of Multibody Systems

1999 ◽  
Author(s):  
Deming Wang ◽  
David Beale
Keyword(s):  
Multibody Systems ◽  
Impact Analysis ◽  
Multibody System ◽  
The Body ◽  
Interference Analysis ◽  
Contact Joint ◽  
Impact Problems ◽  
Point Line ◽  
Two Bodies ◽  
Motion Design

Abstract A new computer aided analysis method for frictionless interference impact problems between two bodies in a constrained multibody system is presented in the paper, which can be used to perform interference analysis and motion design of multibody systems. A virtual contact joint concept is used to detect interference between two bodies and calculate the jump in the body momenta, velocity discontinuities, rebounds and system motion after the interference impact analysis. The interference surfaces can be any geometric element, such as point, line segment, are and circle described by the joint coordinates of the virtual contact joint. The method are very useful to predict and determine the interference time, the types and positions of two impact surfaces. System motion after the interference can be controlled by changing some dynamic parameters in the multibody system.

Active vibration control of spatial flexible multibody systems

2013 ◽  
Vol 30 (1) ◽  
pp. 13-35 ◽  
Author(s):  
Maria Augusta Neto ◽  
Jorge A. C. Ambrósio ◽  
Luis M. Roseiro ◽  
A. Amaro ◽  
C. M. A. Vasques
Keyword(s):  
Vibration Control ◽  
Multibody Systems ◽  
Active Vibration Control ◽  
Flexible Multibody Systems ◽  
Flexible Multibody ◽  
Active Vibration

scholarly journals Multibody Systems with Flexible Elements

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1359
Author(s):  
Marin Marin ◽  
Dumitru Băleanu ◽  
Sorin Vlase
Keyword(s):  
Multibody Systems ◽  
Computer Assisted ◽  
Elastic Bodies ◽  
Algorithmic Analysis

The formalism of multibody systems offers a means of computer-assisted algorithmic analysis and a means of simulating and optimizing an arbitrary movement of a possible high number of elastic bodies in the connection [...]

A three-dimensional immersed boundary method based on an algebraic forcing-point-searching scheme for water impact problems

2021 ◽  
Vol 233 ◽  
pp. 109189
Author(s):  
Bin Yan ◽  
Wei Bai ◽  
Sheng-Chao Jiang ◽  
Peiwen Cong ◽  
Dezhi Ning ◽  
...  
Keyword(s):  
Immersed Boundary Method ◽  
Three Dimensional ◽  
Immersed Boundary ◽  
Water Impact ◽  
Boundary Method ◽  
Impact Problems
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