The Relationship between X-Ray Stress Measured Value and Applied Stress in Elastic/Plastic Deformation Region in Tensile Testing

The Relationship between X-Ray Stress Measured Value and Applied Stress in Elastic/Plastic Deformation Region in Tensile Testing

M. Nakashiro, Y. Takaku, Y. Mitani, A. Kohri

Abstract. Recently in Japan, the 2D detector X-ray stress measurement equipment has developed, and requests of on-site measuring the stress on structural components are increasing. On the other hand, high residual stress, which exceeds its tensile strength stress, is often observed on welded construction parts, and sometimes it causes defects or damage. We report a result of clarified characteristics of X-ray diffraction stress value (XRD) in which exceeds the yield point in the plastic strain region on steel (SM490) and stainless steel (SUS316). For studying the correlation with XRD measurement results and the stress value, we installed flat plate test specimens in the tensile test machine and cyclically loaded to the plastic strain region to simulate the welding structure under load. The XRD measurement values indicated a high correlation with the actual stress value. These results confirm that the XRD measurement values give the actual stress condition of the material under load, irrespective of elastic-plastic deformation. XRD measurement is not only applicable for measuring internal stress but also measuring combination of internal and external stress on a material. Consequently, XRD measurement can also be used to measure the loaded stress conditions of a structure (this stress is also called dead load or static load). Moreover, this outcome expands function of XRD from a specialized measuring method for residual stress to various structural conditions.

Keywords
X-Ray Residual Measurement, Sin2Ψ, True Stress, Elastic Strain, Plastic Strain

Published online 12/22/2016, 6 pages
Copyright © 2016 by the author(s)
Published under license by Materials Research Forum LLC., Millersville PA, USA

Citation: M. Nakashiro, Y. Takaku, Y. Mitani, A. Kohri, ‘The Relationship between X-Ray Stress Measured Value and Applied Stress in Elastic/Plastic Deformation Region in Tensile Testing’, Materials Research Proceedings, Vol. 2, pp 216-222, 2017

DOI: http://dx.doi.org/10.21741/9781945291173-37

The article was published as article 37 of the book Residual Stresses 2016

Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

References
[1] JSMS-SD-5-02, “Standard method for X-ray stress measurement’’, The Society of Materials Science, Japan (2002).
[2] S. Taira, K. Hayashi and N. Urakawa, “X-ray Measurement and Analysis of Residual Stress Induced in Polycrystalline Aluminum by Uniaxial Plastic Deformation”, Journal of the Japan Institute of Metals, Vol.35, No.3, pp189-196(1971).
[3] K. Kojima, “Stress Measurement for X-ray”, Journal of the Society of Materials Science, Japan, Vol.47, No.6, pp.502-509(1952).