IMProVe 2011 - Proceedings

Geometric Product Specification and Tolerancing
An algorithm is proposed which generalises the method. An example shows the
application of the method on an assembly made up of two parts. Lastly, there is a
discussion of the features of this algorithm, developed using the OpenCascade
environment.
Keywords: Geometric tolerancing, Minkowski sum, Polytope, Normal fan
Corresponding Author: Denis Teissandier
Tel.: +33 5 4000 6222
Fax.:+33 5 4000 6964
e-mail: denis.teissandier@u-bordeaux1.fr
Address: University of Bordeaux, I2M – UMR CNRS 5295, 351 cours de la liberation, F-33405 Talence
cedex - France.
Experimental evaluation of convex difference surface
for planar joint study
H. N. Lê (a), Y. Ledoux (a), P. Darnis (a), A. Ballu (a)
(a) Université de Bordeaux – UMR 5295 CNRS - I2M Institut de Mécanique et d'Ingénierie de Bordeaux
Abstract:
In tolerancing, numerous works deal with the theory of tolerance analysis and synthesis of
mechanisms, others deal with verification of isolated parts, but no study has focused
specifically on the metrology of mechanisms. Nowaday, the metrology of mechanisms
begins to be a key parameter for validating the theoretical model of joint.
At first, a measuring system is presented; it allows to determine experimentally joint
behaviours. This device is based on a set of displacement sensors, located outside the
joint, to capture every spatial displacement. From the measures, the three rotations and
three translations of displacement are computed. The originality of the system is to allow
the visualization of the gap hull of the joint. Moreover, the distribution of the local form
defects of the surfaces in contact inside the joint may be determined. In parallel, the
surfaces in contact are measured with an area surface texture measuring instrument.
From these measurements, it is proposed to compute theoretically the gap hull. Finally, a
comparison of both hulls is presented.
Keywords: Gap hull, Difference surface, Joint behaviour, Form defect, Tolerancing
Corresponding Author: Alex Ballu
Tel.: (33)5 4000 66 13
E-mail: alex.ballu@u-bordeaux1.fr
Address: 351 Cours de la libération, 33400 TALENCE.
June 15 th – 17 th , 2011, Venice, Italy
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IMProVe 2011 - Proceedings