Experimental investigation of the influence of the FSW plunge processing parameters on the maximum generated force and torque

The paper presents the results of an experimental investigation, done on the friction stir welding (FSW) plunging stage. Previous research works showed that the axial force and torque generated during this stage were characteristic for a static qualification of a FSW machine. Therefore, the investigation objectives are to better understand the relation between the processing parameters and the forces and torque generated. One of the goals is to find a way to reduce the maximum axial force and torque occurring at the end of the plunging stage in order to allow the use of a flexible FSW machine. Thus, the influence of the main plunge processing parameters on the maximum axial force and torque are analysed. In fact, forces and torque responses can be influenced by the processing parameter. At the end, a diagram presenting the maximum axial force and torque according to the processing parameters is presented. It is an interesting way to present the experimental results. This kind of representation can be useful for the processing parameters choice. They can be chosen according to the force and torque responses and consequently to the FSW machine capacities

Overview of the mean of production used for FSW

The Friction Stir welding process is now introduced in production plants. More and more applications are developed and the most part of the work is now centered on the mean of production to be used. Institut de Soudure and Arts et Métiers ParisTech are working on this subject since mid of 2005. The results of this work is a recognize knowledge on the methodology for qualifying a Friction Stir Welding Equipment [1]. In the same time, and based on this work, Institut de Soudure has bought a new kind of Friction Stir Welding machine based on a KUKA Robot

Statistical model of the tool/workpiece mechanical interactions in FSW

The robotization of the FSW process is facing two challenges which are to support the amplitude of the tool / workpiece mechanical interaction generated by welding and to apply the process parameters and in particular the axial force. To design the control laws of the robot it is necessary to model the mechanical interaction between the tool and the workpiece as function of the fsw process parameters

Maintenance sur les infrastructures de surface

L'objet de ce document est de dresser le bilan de l'activité du Groupe Technical Facilities Management dans le domaine de la maintenance. Ce bilan couvre les activités techniques du génie civil, du chauffage-climatisation et de l'électricité, s'appliquant dans une large majorité au seul secteur tertiaire, tant sur le plan préventif que correctif. Les principaux paramètres indicateurs de l'activité sont situés dans leur évolution au cours des dernières années. Les auteurs abordent également les principaux projets complémentaires de maintenance, qui sont conduits pour maintenir l'état du patrimoine en dépit des restrictions budgétaires, faire face aux problèmes d'obsolescence, de défaillances récurrentes sur certains matériels, et satisfaire aux normes de sécurité. L'incidence positive de ces actions sur le nombre d'interventions de maintenance corrective est également montrée. Enfin, des perspectives de progrès sont dégagées, visant à une gestion davantage prévisionnelle de la maintenance

Qualification of a robotized Friction Stir Welding System

This paper presents an experimental methodology to determine a Friction Stir Welding (FSW) means of production based on the experimental study of the tool / material mechanical interactions generated during the welding operation. These two stages have been identified as being characteristic for the qualification of a FSW equipment. This paper presents the experimental results of the parametric study done on the plunging and welding phases. Ranges of forces and torques diagrams were established according to the processing parameters, in order to qualify a means of production and select the process parameters allowing the operation on the available FSW equipment

Determining the ability of a high payload robot to perform FSW applications

This paper presents an experimental methodology to determine a Friction Stir Welding (FSW) means of production based on the experimental study of the tool / material mechanical interactions generated during the welding operation. These two stages have been identified as being characteristic for the qualification of a FSW equipment. This paper presents the experimental results of the parametric study done on the plunging and welding phases. Ranges of forces and torques diagrams were established according to the processing parameters, in order to qualify a means of production and to select the processing parameters allowing the operation on the available FSW equipment

Robotized FSW – Evolution of forces and torque with nonlinear welds

The main purpose of the article is to study the evolution of the welding forces and torque with non-straight welding path. The main studies performed on forces and torque are usually done on plane straight welding path when the processing parameter are developed. As industrializing robotized FSW, the robot structure deformation under FSW load depends on the forces generated on the tool. Thus, in order to compensate the robot deformation automatically through the control, statistical model giving the welding forces and torque as function of the process parameters is established. This article deals with the study of the forces and torque generated as welding circular and semi-circular welds. The effect of the welding direction (i.e. position of advancing and retreating side) is also analyzed. The objective is to determine if the statistical model giving the welding forces and torque as function of the process parameters developed on straight line can be applied for welding different weld path geometries

Contribution de la consolidation au maintien du patrimoine

Les premiers bâtiments du Laboratoire datent de 1954 et les équipements techniques les plus anciens encore en service dans ces bâtiments datent de 1956. Nombre d'entre eux sont toujours constitués des matériels d'origine qui ont largement dépassé leur espérance de vie normale et ne satisfont plus aux normes de sécurité. La non disponibilité fréquente de pièces de rechange sur des matériels obsolètes, les risques encourus tant par les exploitants que par les utilisateurs du point de vue de la sécurité, et les co ts de maintenance qui ne peuvent être contenus en l'absence de budget d'investissement, ont conduit le groupe ST-TFM, au cours des dernières années, à lancer un minimum de projets de consolidation pour empêcher la dégradation du patrimoine. Ce document synthétise les différentes actions entreprises et montre que l'effort doit être maintenu, voire accru, si l'on veut globaliser vers l'extérieur les opérations de maintenance dans de bonnes conditions

Morphometric variations at an ecological scale: Seasonal and local variations in feral and commensal house mice

The time scales of evolutionary and ecological studies tend to converge, as evidenced by studies that have shown contemporary evolution can occur as fast as ecological processes. This opens new questions regarding variation of characters usually considered to change mostly along an evolutionary time scale, such as morphometric traits, including osteological and dental features such as mandibles and teeth of mammals. Using two-dimensional geometric morphometric approach, we questioned whether such features can change on a seasonal and local basis, in relation to the ecological dynamics of the populations. Our model comprised populations of house mice (Mus musculus domesticus) in two contrasted situations in mainland Western Europe: a feral population vs. two close commensal populations. Mitochondrial DNA (D-loop) provided insight into the diversity and dynamics of the populations. The feral population appeared as genetically highly diversified, suggesting a possible functioning as a sink in relation to the surrounding commensal populations. In contrast, commensal populations were highly homogeneous from a genetic point of view, suggesting each population to be isolated. This triggered morphological differentiation between neighboring farms. Seasonal differences in morphometric traits (mandible size and shape and molar size and shape) were significant in both settings, although seasonal variations were greater in the feral than in the commensal population. Seasonal variations in molar size and shape could be attributed to differential wear in young or overwintered populations. Differences in mandible shape could be related to aging in overwintered animals, but also possibly to differing growth conditions depending on the season. The impact of these ecological processes on morphometric traits is moderate compared to divergence over a large biogeographic scale, but their significance nevertheless underlines that even morphological characters may trace populations dynamics at small scale in time and space