Calibration of the X-Ray Diffraction Technique for Stress Quantification in Metallic (Steel) Structures

The X-Ray Diffraction technique has been widely applied for decades in many industrial sectors for the quantification of residual stresses in metallic parts. The present paper describes the laboratory calibration of this technique with the aim of adapting it to the quantification of global stresses (non residual) in metallic structures, in service for civil engineering and building. A small structure specifically built for this research has been repeatedly loaded at laboratory. In each load level the global stresses in a bar of the structure have been quantified by means of X-Ray Diffraction technique. The experimental procedure allows one to discern the residual stresses and the structural (mechanical) stresses in service. The correlation between the stresses deduced experimentally and the applied stresses is excellent. As conclusion, it can be stated that the X-Ray Diffraction technique as a non-destructive technique, has been calibrated to be used for stress deduction in metallic elements in service.