Modeling, analysis and verification of optimal fixture design

Abstract

Fixture design is an important manufacturing activity which affects the quality of parts produced. In order to develop a viable computer aided fixturing tool, the fixture-workpiece system has to be accurately modeled and analysed. This thesis describes the modeling, analysis and verification of optimal fixturing configurations by the methods of force closure, optimization, and finite element modeling (FEM). Force closure has been employed to find optimal clamping positions and sequencing, while optimization is used for determining the minimum clamping forces required to balance the cutting forces. The developed FEM is able to determine in detail what are the reaction forces, workpiece displacement, deformation in the workpiece and fixtures. In order to produce a more accurate model for predicting the behaviour of the fixture a??workpiece system, the developed FEM includes fixture stiffness, which past models have assumed as rigid bodies. The reaction forces on the locators are experimentally verified. A sensor-embedded experimental fixturing setup was developed to verify the modeling and the data was used to compare with the FEM.