Models for Computer Aided Tolerancing in Design and Manufacturing

Computer Aided Tolerancing (CAT) is an important topic in any field of design and production where parts move relative to one another and/or are assembled together. Geometric variations from specified dimensions and form always occur when parts are manufactured. Improvements in production systems can cause the amounts of the variations to become smaller, but their presence does not disappear. To shorten the time from concept to market of a product, it has been increasingly important to take clearances and the tolerancing of manufacturing variations into consideration right from the beginning, at the stage of design. Hence, geometric models are defined that represent both the complete array of geometric variations possible during manufacture and also the influence of geometry on the function of individual parts and on assemblies of them.

The contents of this book originate from a collection of selected papers presented at the 9th CIRP International Seminar on CAT that was held from April 10-12, 2005 at Arizona State University, USA. The CIRP (Collège International pour la Recherche en Production or International Institution for Production Engineering Research) plans this seminar every two years, and the book is one in a series of Proceedings on CAT. The book is organized into seven parts: Models for Tolerance Representation and Specification, Tolerance Analysis, Tolerance Synthesis, Computational Metrology and Verification, Tolerances in Manufacturing, Applications to Machinery, and Incorporating Elasticity in Tolerance Models.

33 papers by experts from around the world Subjects that range from theoretical models to practical applications Up-to-date methods for modeling manufacturing variations and tolerances in auto and aircraft panels are included Progress in integrating solid modeling and quality-control measurements with standards for geometric dimensioning and tolerancing

Contenu
A Unified Approach to Design of Assemblies Integrating Nominal and Variation Design.- Virtual Gauge Representation for Geometric Tolerances in CAD-CAM Systems.- Modal Expression of Form Defects.- Dependence and Independence of Variations of a Geometric Object.- A Model for a Coherent and Complete Tolerancing Process.- Tolerance-Maps Applied to the Straightness and Orientation of an Axis.- Information Modeling to Manage Tolerances during Product and Process Design.- Relative Positioning of Planar Parts in Toleranced Assemblies.- Geometrical Variations Management in a Multi-Disciplinary Environment with the Jacobian-Torsor Model.- Tolerance Analysis and Synthesis by Means of Deviation Domains, Axi-Symmetric Cases.- Re-Design of Mechanical Assemblies using the Unified Jacobian-Torsor Model for Tolerance Analysis.- Complex Mechanical Structure Tolerancing by Means of Hyper-graphs.- An Efficient Solution to the Discrete Least-Cost Tolerance Allocation Problem with General Loss Functions.- Monitoring Coordinate Measuring Machines by User-Defined Calibrated Parts.- Evaluation of Geometric Deviations in Sculptured Surfaces Using Probability Density Estimation.- How to Automate the Geometrical Tolerances Inspection: A Reverse Engineering Approach.- A New Algorithm to Assess Revolute Surfaces through Theory of Surface Continuous Symmetry.- Statistical Modelling of Geometrical Invariant Sampled Sets.- Simulation of the Manufacturing Process in a Tolerancing Point of View: Generic Resolution of the Positioning Problem.- Surface Best Fit: Generated Distribution of the Real Manufacturing Process.- Position Deviation of a Holes Pattern Due to Six-Point Locating Principle.- Tolerance Assignment Using Genetic Algorithm for Production Planning.- Impact of Geometric Uncertainties Onto theOperating Performance of a Mechanical System.- Influence of the Standard Components Integration on the Tolerancing Activity.- Surfaces Seam Analysis.- Statistical Tolerance Analysis of Gears by Tooth Contact Analysis.- Tolerance Analysis and Allocation using Tolerance-Maps for a Power Saw Assembly.- Error Analysis of a NanoMechanical Drill.- Tolerance Synthesis of Higher Kinematic Pairs.- Geometrical Study of Assembly Behaviour, Taking into Accounts Rigid Components' Deviations, Actual Geometric Variations and Deformations.- Practical Implications in Tolerance Analysis of Sheet Metal Assemblies: Experiences from an Automotive Application.- Predicting Deformation of Compliant Assemblies Using Covariant Statistical Tolerance Analysis.- Elastic Clearance Domain and Use Rate Concept Applications to Ball Bearings and Gears.- Tolerance Verification for Sheet Metal Bending Factors Influencing Dimensional Accuracy of Bent Parts.