Faculty Advisor

Richard D. Sisson

Faculty Advisor

Yiming (Kevin) Rong

Faculty Advisor

Christopher A. Brown

Faculty Advisor

Joseph J. Rencis

Faculty Advisor

Mustapha S Fofana

Faculty Advisor

Juhchin Yang




This study presents Computer-Aided Fixture Design Verification (CAFDV) - the methods and implementations to define, measure and optimize the quality of fixture designs. CAFDV verifies a fixture for its locating performance, machining surface accuracy, stability, and surface accessibility. CAFDV also optimizes a fixture for its locator layout design, initial clamping forces, and tolerance specification. The demand for CAFDV came from both fixture design engineers and today's supply chain managers. They need such a tool to inform them the quality of a fixture design, and to find potential problems before it is actually manufactured. For supply chain managers, they will also be able to quantitatively measure and control the product quality from vendors, with even little fixture design knowledge. CAFDV uses two models - one geometric and one kinetic - to represent, verify and optimize fixture designs. The geometric model uses the Jacobian Matrix to establish the relationship between workpiece-fixture displacements, and the kinetic model uses the Fixture Stiffness Matrix to link external forces with fixture deformation and workpiece displacement. Computer software for CAFDV has also been developed and integrated with CAD package I-DEAS TM. CAD integration and a friendly graphic user interface allows the user to have easy interactions with 3D models and visual feedback from analysis results.


Worcester Polytechnic Institute

Degree Name



Manufacturing Engineering

Project Type


Date Accepted





Fixture Stiffness Matrix, Jacobian Matrix, kinetic model, geometric model, fixture design verification, stability analysis, tolerance analysis, tolearnce assignment, Tolerance (Engineering), Computer-aided design, Computer-aided fixture design