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New Directions in Solid Modeling - What Direct Modeling Means for CAD Educators

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2016 ASEE Annual Conference & Exposition


New Orleans, Louisiana

Publication Date

June 26, 2016

Start Date

June 26, 2016

End Date

June 29, 2016





Conference Session

CAD Within Engineering Design Graphics

Tagged Division

Engineering Design Graphics

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Holly K. Ault Ph.D. Worcester Polytechnic Institute

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Holly K. Ault is an associate professor of mechanical engineering at Worcester Polytechnic Institute. She serves as director of the Melbourne (Australia) Project Center and co-director of the Assistive Technology Resource Center. She received her B.S. in chemistry, and M.S. and Ph.D. degrees in mechanical engineering from WPI in 1974, 1983 and 1988 respectively.

Professor Ault has advised off-campus project students in London, Copenhagen, Stockholm, Windhoek (Namibia), San Jose (Costa Rica), Washington, D.C., Boston, Modesto (Calif.), and Melbourne. In the fall of 2001, she was invited as the Lise Meitner Visiting Professor, department of design sciences, Lund Technical University, Lund, Sweden. Prior to teaching at WPI, she worked as a manufacturing engineer for the Norton Company in Worcester, Mass., and product-development engineer for the Olin Corporation in East Alton, Ill.

Professor Ault’s primary teaching responsibilities include undergraduate- and graduate-level courses in computer-aided design, mechanical design, and rehabilitation engineering. Her research interests include computer-aided mechanical design, geometric modeling, kinematics, machine design, rehabilitation engineering, and assistive technology. She is a member of ASME, ASEE, ISGG and Tau Beta Pi.

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Arnold D. Phillips Jr. Worcester Polytechnic Institute

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Direct modeling is an intuitive approach to creating parts and assemblies without the burden of history-based dependencies. Users can directly edit model geometry using everyday software methods such as “copy/paste” and “drag/drop” without needing to know how the geometry was originally created. Direct modeling creates geometry rather than features so it perfect for conceptual modeling where the designer doesn’t want to be tied down with the inter-dependencies of features and the ramifications making a change might have. The direct modeling approach simplifies design, so pre-planning a modeling strategy is not necessary as compared to history-based modeling. With direct modeling, designers can work within the most common modeling concepts. Similar to the history based modeling, the designer can create a 2D profile and then develop the model using commands like extrude, revolve, etc.

The advent of direct modeling will undoubtedly have a notable impact on the approach to teaching CAD in the undergraduate curriculum. Similar to the shift from 2D drafting to 3D solids, this new approach represents a paradigm shift in the CAD environment. In this paper, we will present the different approaches to direct modeling currently used by the leading CAD vendors and investigate the ramifications of changes in methods used to create and modify geometries, as well as differences in downstream uses for these new models.

Ault, H. K., & Phillips, A. D. (2016, June), New Directions in Solid Modeling - What Direct Modeling Means for CAD Educators Paper presented at 2016 ASEE Annual Conference & Exposition, New Orleans, Louisiana. 10.18260/p.25787

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