Finite element analysis of superfinish hard turning

Yuebin Guo, Purdue University

Abstract

Mechanical properties of the work material are required inputs for any numerical and analytical modeling to predict machining performance. Obtaining mechanical properties of work materials in machining and developing practical 3-D finite element analysis (FEA) models have been identified as two important problems for the future computational mechanics of machining processes. As such, development of a method to estimate mechanical properties of the work material in machining for finite element analysis of a machining process has scientific as well as economic importance. Based on the literature review, a satisfactory method to obtain mechanical properties of the work material in machining has not been available. Cutting tests coupled with cutting models are usually used to estimate average flow stress of the work material. This method can only obtain flow stresses/strains in plastic deformation in a small range of strain, strain rate, and temperature. However, for accurate FEA of machining, mechanical properties in both elastic and plastic deformations for a much broader range are required. In this study, an approach using tensile tests at elevated temperatures has been proposed to estimate mechanical properties for both elastic and plastic deformations in a broad range of strain, strain rate, and temperature in machining. The proposed method has been applied and verified for hard turning AISI 52100 steel (62 HRC). Flow stresses at high strain rates in machining processes can be estimated by making use of the concept of velocity-modified temperature. A practical 3D explicit FEA model has been developed and applied to analyze the superfinish hard turning process using the experimentally determined material properties. A friction model, which decouples sticking and sliding regions, has been established for the tool-chip interface. Flow stress data from tensile tests and cutting experiments are consistent with regard to the velocity-modified temperature. Cutting forces and cutting temperatures from the simulation and the measurement agree. Chip flow and residual stresses were also predicted. FEA sensitivity to the magnitudes of material failure criterion and flow stress was performed and studied.

Degree

Ph.D.

Advisors

Liu, Purdue University.

Subject Area

Mechanical engineering|Industrial engineering

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