Residual Stress Analysis Based on Acoustic and Optical Methods

Abstract

Co-application of acoustoelasticity and optical interferometry to residual stress analysis is discussed. The underlying idea is to combine the advantages of both methods. Acoustoelasticity is capable of evaluating a residual stress absolutely but it is a single point measurement. Optical interferometry is able to measure deformation yielding two-dimensional, full-field data, but it is not suitable for absolute evaluation of residual stresses. By theoretically relating the deformation data to residual stresses, and calibrating it with absolute residual stress evaluated at a reference point, it is possible to measure residual stresses quantitatively, nondestructively and two-dimensionally. The feasibility of the idea has been tested with a butt-jointed dissimilar plate specimen. A steel plate 18.5 mm wide, 50 mm long and 3.37 mm thick is braze-jointed to a cemented carbide plate of the same dimension along the 18.5 mm-side. Acoustoelasticity evaluates the elastic modulus at reference points via acoustic velocity measurement. A tensile load is applied to the specimen at a constant pulling rate in a stress range substantially lower than the yield stress. Optical interferometry measures the resulting acceleration field. Based on the theory of harmonic oscillation, the acceleration field is correlated to compressive and tensile residual stresses qualitatively. The acoustic and optical results show reasonable agreement in the compressive and tensile residual stresses, indicating the feasibility of the idea.

Review on residual stress in selective laser melting additive manufacturing of alloy parts

“…With the improvement of computing efficiency, synchrotron radiation-based scanning Laue X-ray micro-diffraction has been developed into a near real-time quantitative imaging technique at the micro and Nano-scale, which may bring new prospects to the control over residual stress [131]. Micro-CT [126], digital image correlation [83] and displacement sensors [104] accompanied with optical [140] and acoustic [141] methods have achieved many meaningful achievements, and further stimulate the detection and analysis of residual stresses.…”

Opto-Acoustic Technique for Residual Stress Analysis

“…As an example of dissimilar welding, we discuss here a previous analysis [26] on butt-brazing of a carbon steel (skh51) and cemented carbide (V30). Figure 5a illustrates the arrangement of the brazing.…”

Introductory Chapter: New Challenges in Residual Stress Measurements and Evaluation

“…Caterina Casavola*, Claudia Barile, Vincenzo Moramarco and Giovanni Pappalettera Dipartimento di Meccanica, Matematica e Management, Politecnico di Bari, Bari, Italy *Address all correspondence to: caterina.casavola@poliba.it alternative some modifications of the hole drilling method such as the deep hole drilling method [11] and the slitting method [12] are studied and under development for in-depth measurements. In the direction of developing new nondestructive approaches, it appears now promising the possibility to combine optical and acoustic methods [13] to evaluate residual stress through the detection of the variation of the elasticity constant of the material. This is, incidentally, along another path of development followed by scholars in the last years aiming to combine multiple approaches in a single hybrid method (e.g., hole drilling/ring core).…”