Impacts with Friction by Poisson's Law

2013 ◽  
Vol 56 (5) ◽  
pp. 875-881 ◽  
Author(s):  
HongJian Zhang ◽  
CaiShan Liu ◽  
Zhen Zhao ◽  
Bernard Brogliato

Author(s):  
Friedrich Pfeiffer ◽  
Christoph Glocker

Abstract Mechanically impacts with friction include questions of relative kinematics and of constraint dynamics both in normal and in tangential directions. In addition both directions are of course coupled because impulses in one direction influence the behaviour in the other direction, especially when considering the normal impulses stored at the end of the compression phase. Together with the stored tangential impulses it governs the expansion phase. Paper presents a model of such impacts with friction considering a compression and an expansion phase. Some examples illustrate the practical relevancy of the theory.


Author(s):  
Friedrich Pfeiffer

Roller coasters are dynamically multibody systems with unilateral contacts due to the usual raceway design including straight parts and bends. In running down such tracks and passing parts of the track with changing curvature impacts with friction are generated in the track-wheel contacts. The impacts are always connected with large overloads of the wheels sometimes leading to damages. To investigate these problems the roller coaster carriages are modelled as a non-smooth multibody system with impacts and stick-slip processes. The results in terms of wheel loads are used to improve wheel design.


Author(s):  
Friedrich Pfeiffer

Many machine and mechanism processes are accompanied by impacts with friction. They arise by short-time contacts between two or more bodies, and they generate energy losses mainly due to friction in tangential contact directions. During the last two decades a couple of impact models based on the theory of rigid body contact were established connected with the names of Moreau, Fremond and Glocker, which all work quite satifactorily with respect to practical applications, although some examples indicate deviations requiring more investigations with respect to the impact models and the type of examples considered. We shall focus on Glocker’s model, for which some experimental verifications are available by Beitelschmidt. A missing link are energy considerations, which are available, but nevertheless do not provide us with a complete information for all possible cases. The paper tries to fill a bit this gap by founding the investigations on a combined phenomenological and theoretical basis.


Author(s):  
Friedrich Pfeiffer

Abstract Various models for impacts with friction have been proposed, the most successful ones taking into consideration a compression and an expansion phase in normal and tangential direction. Impulses are stored during compression and released with frictional losses during expansion. Stick-slip and detachment phenomena during the impact can be considered by complementarity rules. A corresponding model for impacts with friction is presented and verified by measurements with an impact machine. In addition, some industry applications confirm the theory.


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