Modelling and experimental investigation of a sensor-integrated workpiece-fixture system

Abstract

The dynamic characteristics of a workpiece-fixture system play an important role in deciding the machining accuracy of a workpiece. This paper presents a methodology for measuring and analysing the interaction between a workpiece and fixturing elements. A sensor-integrated fixture system, in which real-time reaction forces on locators are measured through a data acquisition system, has been developed for end milling operations. Reaction forces with respect to cutting forces, location of cutter and clamping forces are monitored using a spectral analyser to estimate the dynamic behaviour of the workpiece-fixture system. Non-linear surface contacts and frictional effects between the workpiece and the fixturing elements are modelled using the finite element method. The FEM model is further verified against the measured force values. This approach is very useful in studying the optimal configuration of a fixture and provides guidelines for constructing an intelligent fixture.