Comparaisons calculs-essais pour le carter d'alimentation d'huile TA96

Report (1996)

On this application, the computed results were in the opposite direction as compared to the physical tests. A sound analysis led to the result that a parasitic deformation was due to clamping deformations ... [more ▼]

On this application, the computed results were in the opposite direction as compared to the physical tests. A sound analysis led to the result that a parasitic deformation was due to clamping deformations. In fact, the three supports of the work were found to be unsufficiently coplanar. [less ▲]

Répartition des forces d'usinage

Report (1996)

In the frame of the feasability study of a machining simulation tool, this report starts from the fact that the concentrated loads which were formerly used are somewhat defective from several points of ... [more ▼]

In the frame of the feasability study of a machining simulation tool, this report starts from the fact that the concentrated loads which were formerly used are somewhat defective from several points of view. A procedure to compute distributed loads is described. [less ▲]

Dual analysis with general boundary conditions

in Computer Methods in Applied Mechanics & Engineering (1995), 122(1-2), 183-192

The dual analysis concept was introduced by Fraeijs de Veubeke [1] as a consequence of upper and lower bounds of the energy. As such bounds exist only in those cases where one type of condition is ... [more ▼]

The dual analysis concept was introduced by Fraeijs de Veubeke [1] as a consequence of upper and lower bounds of the energy. As such bounds exist only in those cases where one type of condition is homogeneous, it is commonly admitted that a dual error measure does not exist with general boundary conditions. This paper presents a re-examination of the dual error measure by a way which avoids any use of upper and lower bounds of the energy. It is found that such an error measure holds whatever the boundary conditions be. Furthermore, it is not necessary to obtain the approximate solutions by a Rayleigh-Ritz process, so that the second analysis, which seemed necessary in the original dual analysis concept, may be replaced by any admissible approximation. This implies the possibility of a dual error measure at a simple post-processor level. [less ▲]

Procedures de limitation des cas de charge

Report (1995)

In the frame of the feasability study of a machining simulation tool, this report is devoted to special procedures allowing a reduction of the computed load cases in order to reduce the computational time.

Recommandations relatives aux maillages

Report (1995)

In the frame of the feasability study of a machining simulation tool, this report is devoted to the obtention of a suitable finite element mesh of the work.

Catalogue des cas-tests avec justification des motifs

Report (1995)

In this first report of a research for RENAULT, a preliminary list of benchmarks is defined.

Modélisation du brochage

Report (1995)

In the frame of the feasability study of a machining simulation, this report is devoted to the modelling of the broaching process

Prise en compte de l'enlèvement de matière dans le calcul des raideurs

Report (1995)

In the frame of the feasability study of machining simulation, this report is devoted to the study of the stiffness variation during the machining process

Prévision analytique des défauts d'usinage en chariotage

Report (1994)

This report presents an analytical approach leading to a prediction of the form errors arising when turning a bar, in the three classical fixture configurations. This study consists in determing the ... [more ▼]

This report presents an analytical approach leading to a prediction of the form errors arising when turning a bar, in the three classical fixture configurations. This study consists in determing the radial displacement at the tool end, due to the cutting forces. This displacement, will be retreived with the opposite sign, as a diameter error. Traditional analyses only consider the passive component of the cutting force. Here, the effect of the feed force is also considered. [less ▲]

Problèmes elliptiques avec liaisons

Report (1994)

In this report, the theory of constrained elliptical problems is presented. Two classes of methods are used to solve such problems, which are the dualization and the penalty method. In the first one, use ... [more ▼]

In this report, the theory of constrained elliptical problems is presented. Two classes of methods are used to solve such problems, which are the dualization and the penalty method. In the first one, use is made of Lagrange multipliers. The justification of this method has been given by Brezzi in 1974. This theory is presented in the present report by a particularly simple way, where use is made of elementary hilbertian geometry. Our step, which consists in building the solution, emphasizes the natural character of Brezzi's conditions. Extending this analysis, it was rational to also examine the penalty method, which is often preferred because its simpler implementation. It is shown that the convergence of this method necessitate some hypotheses which are in most cases equivalent to Brezzi's conditions. [less ▲]