Search results for "physics.class-ph"

A finite element analysis of high- speed metal forming processes

1991

International audience

Une approche maîtrisée de la mesure 3D sans contact des pièces mécaniques par scanning laser, a Controlled Approach of the 3D Inspection of Mechanica…

2009

International audience

Measurement of 3D Displacement fields using 3D Laser and CCD Camera

2013

International audience; Many applications dealing with the mechanical behavior of materials require the measurement of displacement fields or deformation fields. For this type of measurement, optical methods have become unavoidable due to their non-intrusive approach, their high spatial resolution, their high sensitivity, the large size of their examinated field, and the increasing power of the computers that now allow the processing of huge quantities of data. In this context we have developed a system for measuring 3-D displacement fields using CCD camera and 3D laser scanner .This method allows the measure of the 3-D displacement field using at least two pairs of stereoscopic images of a…

PTMs developments for the appearance control on high-added value surfaces

2011

International audience; In many areas of activity, the value of a product depends greatly on the perceived quality, including visual one. This work aims to better control sensory perception of products with high added value, especially on the first step of the visual control: the detection, or localization of anomalies in appearance to the surfaces. Companies have controllers, specially trained to locate and evaluate anomalies. These specialists have a higher sensitivity for the detection and evaluation of defects as a potential buyer for example, and this higher acuity is generally completed by a weighting of the intensity of defects according to their location. However, there is still gre…

Tight Fit Desing Taking Into Account Form and Surface Defects

2002

3D Full Field Measurement Based on Micro-geometrical Texture Patterns

2006

International audience; The work presented is based on the laser scanning device that is now currently used in the reverse engineering or tri-dimensionnal inspection domains. The interest of this technique is to measure directly the point clouds in 3D coordinates. That permits to reduce the approximations due to the different correlations made in grey level images stereo-correlation. The sensor is mounted on a CMM that moves it and gives it a good orientation in the measurement space.The pattern is determined by the natural or artificially created micro-geometry (roughness) of the surface product. A depth image is obtained after filtering of the shape of the object. This filtering can be ca…

I.D.A New Model for the Design of Tight Interference Fit Taking Into Account the Surface Texture M.M.E'2000

2000

International audience; The tight interference fit is very largely applied in industry, but, in all proposed models of calculation, one supposes that the contact interfaces are always perfect which leads us to establish some limits which are not only contrary to the grip principle but also greatly increase production costs. This paper presents a new model that takes into account the macro and micro-geometrical defects for calculating the contact pressure. We show that it is possible to reduce the cost and assure the fit resistance. The form defect can be integrated in FEM codes and the surface texture can be represented by a loss of interference due to the plastic strains of the asperities.…

Three Dimensional Modelling of a Shrinkage Fit in Taking into account the Form Defects

1998

International audience; Today, manufacturing products must meet more and more severe specifications. The different parts composing the product often necessitate high dimensional precision, which increases the difficulties for a large series production. Then it it necessary to optimize dimensioning of the different components in an economic context. In the case of small dimensional fits, there is an influence of the micro-geometry (form of defect, roughness) and time of the process on the geometrical characteristics of the assembly. At the time of conception, it is necessary to obtain a good specification that relates the product functionalities with the best cost. The objective study of thi…

Specification analysis and 3D inspection without contact

2009

International audience

Analyse de la mesure des pièces 3D complexes

2005

International audience