The problem of flexible assemblies
The Lurpa studies in particular the problems posed by assemblies of parts, whether these assemblies call upon large numbers of parts or flexible large parts like in aeronautics. Indeed, the functional dimensioning methods based on the definition of dimensions (minimum and maximum admissible values for a part and traditional theory of dimension chains) do not make it possible to avoid in practice the difficulties resulting from geometric defects during assemblies. This point represents a limitation of productivity and a significant cost for the industries which face it.
On the one hand, it is necessary to develop measurement methods integrated into the manufacturing process, in order to detect deviations from the desired functional values as soon as possible.
On the other hand, it is necessary to offer an approach that allows to take into account, as soon as possible, the effective deviations of produced parts. This is in order to update the digital model of an assembly and allow it to reflect the real variations that have to be taken into account for the production of the remaining parts of the assembly.
Example of deviations of a real part from the specification and adaptation in situ
Updating the digital model (DMU : Digital Muck-Up) with the values of a real part during the manufacturing / assembly process.
Publications
A Reverse-Engineering Approach for the Management of Product Geometrical Variations during Assembly
J.-L. Gregorio, C. Lartigue, F. Thiebaut, H. Falgarone
Advances on Mechanics, Design Engineering and Manufacturing II (JCM2018), Springer
Consideration of Working Conditions in Assembly Tolerance Analysis
T. Liu, Z. Zhu, Y. Cao, N. Anwer, J. Yang
15th CIRP Conference on Computer Aided Tolerancing - CIRP CAT 2018, 11-13 June 2018, Milano, Italy
Evaluation of the shape deviation of non rigid parts from optical measurements
F. Thiebaut, C.Lacroix, L. Andolfatto, C. Lartigue
International Journal of Advanced Manufacturing Technology, 88(5-8), pp. 1937-1944, DOI: https://doi.org/10.1007/s00170-016-8899-3, 2017
A Domain Ontology for Assembly Tolerance Design
Y. Qie, L. Qiao, Y. Cui, N. Anwer
ASME International Mechanical Engineering Congress and Exposition (IMECE) 2017, Tampa, Florida, USA, 3-9 November 2017
Unified Variation Modeling of Sheet Metal Assembly Considering Rigid and Compliant Variations
C. NA, L. QIAO, N. ANWER
Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, Volume 229, 3, pp. 495-507, 2015
Numerical process based on measuring data for gap prediction of an assembly
C. Lacroix, L. Mathieu, F. Thiebaut, M. Douilly, H. Falgarone
Procedia CIRP, 13th CIRP Conference on ComputerAided Tolerancing, 27:97-102.
Caractérisation géométrique des assemblages flexibles par la mesure
C. Lacroix
Thèse de l'ENS Cachan, 240 pages, juillet 2015