Automatic modification of part geometries subject to manufacturing constraints using fuzzy logic

There is frequently a need for algorithms capable of automatic modification of geometric models in response to manufacturing process constraints. Designers typically initiate product models using ideal, exact geometry; however, several non-traditional manufacturing processes frequently require slight modifications to the ideal model to accommodate various manufacturing process constraints. These modifications can be difficult, complex, and tedious to compute. For instance, metal-ceramic brazing requires adjustments to the part geometry primarily to accommodate thermal expansion and to allow for the insertion of a narrow braze-filler gap. These adjustments depend on the particular geometry, material properties, and processing parameters. Any modification to these product model parameters necessitates extensive recomputation to reestablish a manufacturable part geometry. This thesis demonstrates in part the integration of geometry into the overall product model by having the non-geometric parts of the product model provide feedback to the geometry by means of automatically modifying its shape. The methodology is demonstrated in a prototype model which introduces the concept of auxiliary geometric structures. In particular, the auxiliary geometric structures provide a mapping between the designer's intent and the part geometry described in the solid model. The designer's intent is represented in a rule base for metal-ceramic brazing that is controlled by fuzzy logic. This rule base aids the user in quantifying and generating from the auxiliary geometric structures the geometric modifications needed to conform with a complex set of rules derived from both analytic and empirical work in metal-ceramic brazing

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Mechanical Engineering

Department dc:contributor.department

Mechanical Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1996

Author dc:creator

• Bass, Henry Morgan

Chair dc:contributor.committeechair

• Bohn, Jan Helge

Committee members dc:contributor.committeemember

• Myklebust, Arvid
• Mitchiner, Reginald G.

• geometric modifications

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

etd-10072005-094854

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/45086