Research on the Test Method of Machining Stress Based on the Instrumented Indentation Test

College of Mechanical Engineering and Applied Electronics Technology, Beijing University of Technology, Beijing, 100124, China

Abstract

The main objective of this study is to measure the distribution of machining stress by the instrumented indentation test (IIT). Finite element method (FEM) was performed to investigate the influences of tensile stress and compression stress on the indentation response (Load-displacement curves, average contact pressure and contact area). The thicknesses of machining stress layer under turning and grinding processing ways were obtained by layer stripping method based on instrumented indentation technique. Results indicate that the machining stress brings complex stress state. Under the same load, the corresponding indentation displacement increases while the indentation plastic work, contact area and average contact pressure decrease with the increases of machining stress (from compressive stress to tensile stress). Tensile stress does just the opposite. In addition, the layer thicknesses of the machining stress for turning and grinding members were measured by instrumented indentation method, results agree with X-ray method and demonstrate the effectiveness of the proposed approach.