Search results for "physics.class-ph"
showing 10 items of 334 documents
Prédiction de cycle et stratégie de gestion énergétique basée sur une méthode d’optimisation globale
2017
International audience; La nécessité de prédire le cycle de conduite d’un automobiliste afin d’améliorer sa gestion énergétique et ainsi réduire la consommation de carburant a été démontré (Debert, Quigley). Dès lors, il serait aisé d’appliquer une méthode d’optimisation globale, telle que la Programmation Dynamique (DP en anglais), pour obtenir la stratégie optimale. Cette méthode est déjà utilisée dans de nombreuses applications (Sciarretta), mais au quotidien nombreux sont les facteurs environnants qui peuvent perturber les conditions de circulation (météo, travaux, accidents....) et impacter le cycle de conduite. Il est donc nécessaire d’élaborer une stratégie adaptative en temps réel. …
A few remarks about the computer implementation and the verification of some hyperelastic constitutive laws and an illustration with the mechanical r…
2022
In this short technical note, we are interested in the constitutive equations used to model macroscopically the mechanical function of soft tissues under mechanical loading. Soft tissues have the ability to undergo large elastic reversible deformations under quasi-static loading and are usually modelled using hyperelastic constitutive laws. Several constitutive equations have been defined in the literature by means of strain components or strain invariants isotropic hyperelastic models. This short technical note recalls how to derive the weak form for hyperelasticity equations, and how this weak form can be linearized. It also presents a semi-analytical solution for a simplified geometry re…
Multi-scale analysis of surface topographies by modal filtering
2012
International audience; This work introduces an innovative method for the multi-scale analysis of surface topographies, which consists of applying a method based on a new parameterization. This kind of surface parameterization refers to natural modes of vibration, and is therefore named modal parameterization. It allows us to characterize the form, waviness and roughness defects of a surface. This parameterization opens up new fields of analysis, such as the appearance quality of surfaces. It is thereby possible to decompose a measured surface in a vector basis, of which vectors are represented by plane natural eigenmodes sorted by frequency and complexity. Different filtering operations ca…
Good practices and uncertainty assessment process on AACMM
2017
International audience; This paper presents a methodology of evaluating the performance of Articulated Arm Coordinate Measuring Machines (AACMM) for general acceptance-based on the manufacturer's specifications, and on site-based mainly on the application requirements. The first part of this paper takes stock of ISO 10360-12: 2016 standard, which defines the tests that the AACMM user should perform to validate or not the performance of his machine. The various tests recommended by the standard are analyzed and their practical usefulness is explained. In the second part of the paper, an on-site uncertainty estimation methodology is proposed. The interest of the on-site verification methodolo…
PROPOSITION OF AN INTERIM STANDARDIZED TEST FOR ARTICULATED ARM COORDINATE MEASURUNG MACHINE
2018
International audience; Improving the kinematic calibration of a coordinate measuring arm using configuration analysis Precis. Eng. 50 171-82 1. Comparison of the AACMM mechanical deformation during the ISO 10360-12 test and the interim test. 2. Study the possibility of calibration of an AACMM with the proposed interim test, or a similar test (study already engaged). Note: The recommendations concerning the repetition and calculation were detailed in [1] and the recommendations concerning the length of the small artifact and the directions of measurement will be detailed in our coming work.
Modèle théorique pour estimer les incertitudes de positionnement de l'effecteur d'un robot parallèle à câble plan
2018
International audience; Les robots parallèles à câbles se développent de plus en plus pour diverses applications. Leur principal avantage réside dans leur capacité de déplacement très rapide sur des distances qui peuvent être importantes. Les déplacements s'effectuent grâce à l'enroulement du câble sur un cabestan. La commande de ces robots est réalisée en pilotant le couple appliqué à chaque câble la position d'équilibre dynamique repose donc sur l'équilibre des efforts appliqués à l'effecteur. La mesure de la position se fait donc de manière indirecte et sans boucle de retour. Pour intégrer ces robots dans un dispositif métrologique, il est nécessaire d'estimer les incertitudes de positio…
Etude du comportement en fatigue d’un composite lin-époxy soumis à un vieillissement hydro-thermique.
2018
International audience
Bio-composites for structural urban outdoor applications - A study of the impact of fiber content on the durability of flax fiber-reinforced epoxy co…
2018
International audience
Modelling an Improved NOL Ring Test Using a Reduced Volume Method for the Characterisation of Composite Cylinders
2019
International audience
YETI: YET another Iga code
2023
YETI is a library offering an implementation of IsoGeometric Analysis based on NURBS and B-Splines. It is published under the GNU Lesser General Public Licence and comes in the form of a Python library allowing the user to enter the input data of a NURBS arametrization (as a text file inspired from Abaqus input files syntax). Stiffness and mass matrices and right hand side vector are computed to form linear systems for solving mechanical or thermal problems. Solid or Kirchhoff-Love shell elements are available.In the context of shape optimization, a NURBS parametrization can be set up with design variables based on control points position. YETI can compute the analytical sensitivities [1] o…