This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Predicting Assembly Performance with Featurized Datum Flow Chains
Technical Paper
1999-01-2271
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
Throughout the development cycle of an assembled product, design and manufacturing engineers commonly perform ad hoc studies to determine whether their creation will meet its dimensional objectives. More simply, they answer the question, “will it go together and work right the first time?” These studies usually involve adding the maximum tolerance allowances in a single direction to find the maximum possible error. Known as a “worst case” study, this method underestimates the accuracy of an assembly because it assumes each part is always manufactured at the extremes of its specification limits. This paper proposes and describes the featurized datum flow chain as an adaptive and comprehensive alternative for calculating predicted variation in characteristics of assemblies. The paper advances prior research performed for the Lean Aircraft Initiative at the Massachusetts Institute of Technology, and it offers an example for completing an assembly study. The featurized datum flow chain captures the load sequence, part constraint, and feature associations for an assembly in a format that can be widely understood and reused. By adding manufacturing capability tolerances to the features in the chain, a user can complete simple root-sum-square calculations to find the predicted error in the assembly. The results of the study are more accurate than worst case findings because root-sum-square mathematics combines probability distributions of the tolerances. Furthermore, the datum flow chain provides a thorough picture of the entire assembly process to its users. Such common understanding is valuable to the design community in ways that reach far beyond tolerance studies.
Recommended Content
Technical Paper | Current Growth in Utilization of the Automated Tape Layer Process |
Technical Paper | Low-Weight, Low Cost AC/DC Converter for the V-22 |
Technical Paper | Turbine Engine Technology and Cost |
Authors
Topic
Citation
Schwemmin, R., "Predicting Assembly Performance with Featurized Datum Flow Chains," SAE Technical Paper 1999-01-2271, 1999, https://doi.org/10.4271/1999-01-2271.Also In
References
- Mantripragada, R. Whitney, D.E. The Datum Flow Chain: A Systematic Approach to Assembly Design and Modeling Research in Engineering Design 10 1998 150 165
- Mantripragada, R. Whitney, D.E. Modeling and Controlling Variation in Mechanical Assemblies using State Transition Models IEEE Transactions on Robotics and Automation 15 1 1999
- Lee, D. J. Thornton, A. C. Key Characteristics for Agile Product Development and Manufacturing Agility Forum 4th Annual Conference Proceedings 1995
- Foster, L. W. Geo-Metrics III. The Application of Geometric Dimensioning and Tolerancing Techniques (Using the Customary Inch System) Addison-Wesley Publishing Company Reading, MA 1994
- Kiemele, Mark J. Schmidt, Stephen R. Berdine, Ronald J. Basic Statistics. Tools for Continuous Improvement. Fourth Edition Air Academy Press LLC, Colorado Springs, CO 1997 9.8 9.13
- Cunningham, T. W. Whitney, D. E. The Chain Metrics Method for Identifying Integration Risk During Concept Design DETC paper DETC98/DTM-5662, ASME DETC Atlanta, GA Sep. 1998
- Whitney, D. E. “A Prototype for Feature-Based Design for Assembly,” ASME Journal of Mechanical Design 115 4 Dec. 1993 723 34