Search results for "Restitution"
showing 10 items of 50 documents
On the friction/tangential restitution problem: Independent friction-restitution modeling of sphere rebound with arbitrary spin
2023
Most descriptions of collision events introduce coefficients of friction and tangential restitution which vary significantly with the impact angle, in contrast with the independence of the normal coefficient of restitution with this parameter. A redefinition of the coefficients of friction and tangential restitution based on the idea that friction and restitution effects can be treated as being mutually independent, provides a satisfactory description of experimental data using a ‘constant’ restitution coefficient independent on the impact angle. This independent friction-restitution modeling is developed here for the rebound of a homogeneous sphere having an arbitrary spin on a rough massi…
Analysis of oblique rebound using a redefinition of the coefficient of tangential restitution coefficient
2013
Abstract A redefinition of the coefficient of tangential restitution based on the separation of friction and restitution effects is presented. Using this modified coefficient of tangential restitution and the usual definitions of the coefficients of normal restitution and sliding friction, a description of oblique impacts in both stick and slip regimes is obtained. This, description, which is tested with available rebound data in literature, avoids sharp (apparent) variations in the coefficient tangential restitution with impact angle and can justify anomalous results reported by Calsamiglia et al. (1999) .
Fait générateur d'une créance de restitution. Le fait générateur de la créance de restitution de droits de douane est le fait juridique à l'origine d…
2007
International audience; (Com. 23 janv. 2007, pourvoi n° 05-13.995, arrêt n° 72 F-P+B, Loeuille c/ Sté Xerox Europe limited, D. 2007. AJ. 448, obs. A. Lienhard)
Créances postérieures privilégiées. Créance de restitution résultant de l'infirmation d'une décision de justice portant condamnation au profit du déb…
2014
International audience; (Com., 17 décembre 2013, n° 12-28.158, arrêt n° 1244 F-D, Verraccia ès qual. c/ Sté Carrefour France, JurisData n° 2013-030117 ; JCP 2014. 636, n° 9, obs. Ph. Pétel ; RJDA 5/2014, n° 455)
On stiffness and damping of vibro-impact dynamics of backlash
2021
We consider the instantaneous stiffness and damping of the vibro-impact in a backlash pair. Opposed to the existing and mostly used models of the backlash, we address the problem of contact and separation, and the associated force propagation within a mechanical pair, from a viewpoint of the vibro-impact dynamics. We discuss the impact forces with the coefficient of restitution as a principal factor which shapes the transient backlash response.We show that a common approach to modeling the backlash by means of a dead-zone in a restoring force is unsuitable for correctly capturing the mechanical impact. We exemplary demonstrate a qualitative accord between an experimental backlash response a…
Independent friction-restitution modeling of two-disk collisions
2021
[EN] The oblique collisions between two axisymmetric disks moving on a flat horizontal surface are described in terms of impact modeling based on the assumption that normal and tangential restitution mechanisms operate independently of friction. Describing these mechanisms in terms of the usual Coulomb formulation, the model allows for an interpretation of some ¿anomalous¿ experimental data reported in the literature. These experimental data, corresponding to the variation of the coefficients of friction and tangential restitution with the impact angle, remained unexplained in classic formulations, are understood within the framework of the independent friction-restitution closure. Experime…
Créance de restitution dont le fait générateur est postérieur au jugement d'ouverture
2018
International audience; (Com. 9 mai 2018, n° 16-24.065, arrêt n° 386 F-P+B, Sté Ducoin ingénierie et concepts c/ Sté MJ Synergie, ès qual., D. 2018. 1005)
Digital Restitution of Cultural Goods: In Search of a Working Model
2023
AbstractThe paper deals with the problem of digital restitution of art to post-colonial and postdependency countries. A new model of digital restitution composed of two elements: creation of a digital copy with a NFT attached and creation of new property right in a physical and digital object has been proposed. A system of balances between the rights and duties based on the prior user concept has been developed.
Analysis of microsphere oblique impact with planar surfaces based on the independent friction-restitution approach
2020
The independent friction restitution closure (IFR) previously applied to describe planar oblique impact of a homogeneous sphere on an infinitely massive rough plane is applied here to microsphere collisions and is extended to describe horizontal launch experiments. The model provides analytical solutions of the motion equations based on a unique set of values of the coefficients of normal and tangential restitution and friction. Comparison with experimental data in literature for the impact of microspheres of diameter <100 mu m yields a satisfactory agreement between experimentation and theory.
A 3D REWORKING OF THE URBAN TRANSFORMATIONS OF PALERMO IN RECENT HISTORY FOR A HYPOTHESIS OF A "CITY MUSEUM" BASED ON DIGITAL VISUALIZATIONS
2021
Abstract. The objective that drives this research is given by a multitude of information which, in addition to the contribution of technology, allows us to study, analyze, verify and remodel the sites, monuments and evolutions of the city through graphic processes of perspective restitution that start from the analysis of historical photos. The drawing methods, the digital graphic rendering and through the aid of geometric techniques, contribute to the reconstruction of projects and architectures that are now lost, this is possible thanks to the methods of perspective, axonometry and three-dimensional restitution.This remarkable photographic heritage belonging to Palermo, but also to any ot…