An Integrated Methodology for Workpiece-Fixture System Stiffness Calculation and Error Control

The deformation error for the machining of thin-walled part has a great influence on the machining quality of the part. However the traditional methodologies are still unsuccessful in studying the influence between the workpiece-fixture system´s stiffness and machining errors of part. In this paper a framework to curb the machining errors based on the deformation of workpiece-fixture system is provided. By the quasic static force analysis of workpiece, a new method to compute the stiffness of workpiece-fixture system is presented and the contact analysis in finite element analysis (FEA) and multi-nonlinear calculation are avoided. Further, the analytic model for machining errors caused by the deformation of workpiece-fixture system is given. Based on the FEA and neural networks, cutting parameters have been optimized under the given machining errors caused by the deformation of workpiece-fixture system, so that the errors can be controlled. Finally, a case study has been used to validate the proposed model.