Ph.D. Proposal Presentation by Haiyan Deng
Thursday, May 19, 2005

(Dr. Shreyes N. Melkote, Chair)

"Analysis and Synthesis of Fixturing Dynamic Stability and Part Quality in Machining"

Abstract

A machining fixture is used to establish and maintain the required position and orientation of a workpiece in a machine tool and plays a key role in determining the operational safety and final product quality. The majority of prior research work on machining fixtures treats the fixture-workpiece system as quasi-static and ignores the dynamic effects. In relatively aggressive machining processes, however, dynamic effects must be considered because they significantly affect the fixture-workpiece system behavior. This work is aimed at developing a model-based framework for analysis and synthesis of arbitrarily configured fixture-workpiece systems with an emphasis on fixturing dynamic stability and desired part quality in machining. Using the models developed in this work, insight into the effects of fixture-workpiece system dynamics and material removal on workpiece stability in the fixture and part quality will be obtained.

This work will focus on the following tasks: i) develop a systematic procedure to analyze the dynamic stability of a fixtured workpiece during machining; ii) quantify the part quality error due to the fixture-workpiece dynamics; iii) investigate the sensitivity of fixture dynamic performance measures to fixture parameter imprecision; iv) optimize fixture design to achieve workpiece stability in the fixture and desired part accuracy; v) experimentally validate the models and procedures developed in this work.

The expected impact of this work is twofold. First, it will lead to an improved understanding of the dynamic behavior of fixture-workpiece systems and the impact of dynamic effects on fixture performance. Second, the proposed approaches are generic and can provide manufacturers with scientifically based reliable simulation tools for evaluating the effectiveness of existing fixtures or designing new optimum fixtures to manufacture products with desired quality. The model-based framework can be used individually or integrated into CAD/CAM systems as a CAFD (computer-aided fixture design) module.