FEM-based prediction of workpiece transient temperature distribution and deformations during milling

In high-speed dry milling of thin-walled parts, the cutter-workpiece temperature rises asymptotically with cutting speed, causing excessive cutter tooth wear and workpiece thermal expansion, which in turn reduces the cutter life and produces dimensional and geometrical variabilities in the machined part. Therefore, a basic understanding of the thermal aspect of machining and the effecting parameters is essential for achieving better part quality with improved productivity. This paper presents a transient milling simulation model to assist manufacturing engineers in gaining in-depth understanding of the thermomechanical aspects of machining and their influence on resulted part quality. Based on the finite-element method approach, the model can predict transient temperature distributions and resulted elastic-plastic deformations induced during the milling of 2.5D prismatic parts comprising features like slots, steps, pockets, etc. The advantages of the proposed model over previous works are that it (1) performs feature-based machining simulation considering transient thermomechanical loading conditions; (2) allows modeling the effects of coolant on convective heat transfer rate; and (3) considers the nonlinear behavior of the workpiece due to its changing geometry, inelastic material properties, and flexible fixture–workpiece contacts. The prediction accuracy of the model was validated with experimental results obtained during the course of the research work. A good agreement between the numerical and experimental results was found for different test cases with varying part geometries and machining conditions.

[1]  Svetan Ratchev,et al.  Milling error prediction and compensation in machining of low-rigidity parts , 2004 .

[2]  James Wallbank,et al.  Cutting temperature: prediction and measurement methods—a review , 1999 .

[3]  T. Özel,et al.  Determination of work material flow stress and friction for FEA of machining using orthogonal cutting tests , 2004 .

[4]  Li Zheng,et al.  Optimal fixture design in peripheral milling of thin-walled workpiece , 2006 .

[5]  Svetan Ratchev,et al.  Error compensation strategy in milling flexible thin-wall parts , 2005 .

[6]  Fritz Klocke,et al.  Radiation Thermometry at a High-Speed Turning Process , 2004 .

[7]  Horacio T. Sánchez,et al.  Analysis and compensation of positional and deformation errors using integrated fixturing analysis in flexible machining parts , 2006 .

[8]  Mark R. Miller,et al.  Experimental Cutting Tool Temperature Distributions , 2003 .

[9]  Andrew Y. C. Nee,et al.  Advanced Fixture Design for FMS , 1995 .

[10]  Alan T. Zehnder,et al.  Measurements and Simulations of Temperature and Deformation Fields in Transient Metal Cutting , 2003 .

[11]  Yusuf Altintas,et al.  Prediction of tool and chip temperature in continuous and interrupted machining , 2002 .

[12]  S. J. Hu,et al.  An Integrated Model of a Fixture-Workpiece System for Surface Quality Prediction , 2001 .

[13]  John S. Agapiou,et al.  Metal Cutting Theory and Practice , 1996 .

[14]  Huaizhong Li,et al.  Modelling of cutting forces in helical end milling using a predictive machining theory , 2001 .

[15]  Sun Fanghong,et al.  Experimental research on the dynamic characteristics of the cutting temperature in the process of high-speed milling , 2003 .

[16]  Andreas Müller,et al.  Elimination of Redundant Cut Joint Constraints for Multibody System Models , 2004 .

[17]  P. Zeng,et al.  Three-dimensional thermo-elastic-plastic coupled FEM simulations for metal oblique cutting processes , 2005 .

[18]  Jehnming Lin,et al.  Inverse estimation of the tool-work interface temperature in end milling , 1995 .