Mod\'elisation et \'evaluation du comportement dynamique d'une structure de machine outil UGV pour la pr\'ediction des d\'efauts g\'eom\'etriques

TL;DR

This paper develops a finite element modeling framework to evaluate the dynamic behavior of high-speed machining centers, aiming to predict and minimize geometric deviations caused by structural deformations during operation.

Contribution

It introduces a specific finite element model and calculation methodology to assess geometric deviations in UGV machine tool structures during high-speed trajectories.

Findings

Finite element model effectively predicts structural deformations.

Method enables optimization of machine design and kinematic parameters.

Results assist in reducing geometric errors during machining.

Abstract

To achieve better performances in term of productivity, High Speed Machining centers have increasing kinematical characteristics. High accelerations caused by the trajectory execution dynamically load mechanical structure, axes and joints. Such deformations of mechanical components a ect the actual position of the tool in the machining frame. Hence, these gemetrical deviations make the machined geometry of the part vary from the expected one. Within the context of managing the HSM process, this study develops a framework and choice of nite element model to evaluate the structure dynamical behavior of a HSM center. Based on the proposed model, a calculation method is detailed to evaluate the geometrical deviations induced by the trajectory execution. The presented works can thus be used as a tool for the structure design of machine, the adjustment and the optimization of kinematical parameters for machining. --- Pour atteindre des performances accrues en terme de productivit\'e, les centres d'Usinage Grande Vitesse poss\`edent des caract\'eristiques cin\'ematiques \'elev\'ees. Les fortes acc\'el\'erations mises en jeu lors de l'ex\'ecution des trajectoires sollicitent dynamiquement la structure et les liaisons. Les d\'eformations engendr\'ees peuvent alors se r\'epercuter sur la position effective de l'outil par rapport \`a la pi\`ece cr\'eant des \'ecarts g\'eom\'etriques par rapport \`a la g\'eom\'etrie attendue. Dans un contexte de ma\^itrise du processus de r\'ealisation de pi\`eces en UGV, les travaux d\'evelopp\'es pr\'esentent une d\'emarche et un choix de mod\'elisation \'el\'ements finis pour \'evaluer le comportement dynamique d'une structure de centre UGV. Bas\'e sur ce mod\`ele, une m\'ethodologie de calcul est propos\'ee pour \'evaluer les \'ecarts g\'eom\'etriques g\'en\'er\'es lors de l'ex\'ecution de trajectoires types. Ces travaux constituent ainsi une voie pour le dimensionnement de structure, le r\'eglage et l'optimisation des param\`etres cin\'ematiques pour l'usinage.