Application of Instrumented Indentation Technique to Evaluate Residual Stress and Stress Directionality
The instrumented indentation technique (IIT) is a powerful method for evaluating mechanical properties of materials such as elastic modulus, tensile strength, fracture toughness and residual stress. Especially, IIT is a promising alternative to conventional methods of residual stress measurement such as hole drilling, saw cutting, X-ray/neutron diffraction, and ultrasonic methods because of its various advantages of nondestructive specimen preparation, easy process, characterization of material properties on local scales and measurement of in-service structures. Evaluation of residual stress using IIT is based on the key concepts that the deviatoric-stress part of the residual stress affects the indentation load-depth curve and that the quantitative residual stress in a target region can be evaluated by analyzing the difference between the residual stress-induced indentation curve and residual stress-free curve. To verify the applicability of the suggested technique, indentation tests were performed on the welded zone.
H.S. Lee, I.S. Yoon and M.H. Aliabadi
M. J. Choi et al., "Application of Instrumented Indentation Technique to Evaluate Residual Stress and Stress Directionality ", Key Engineering Materials, Vols. 385-387, pp. 889-892, 2008