Stress Dependence on Relaxation of Deformation Induced by Laser Spot Heating

• Published in: Materials Vol. 15; no. 18; p. 6330
• Main Authors: Murata, Yuma, Sasaki, Tomohiro, Yoshida, Sanichiro
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 13.09.2022; MDPI
• Subjects: Alloys; Aluminum base alloys; Analysis; Cameras; Contact stresses; Deformation; Evaluation; Heat; Infrared heating; Infrared lasers; Interferometry; Investigations; Laser beam heating; Lasers; Measurement techniques; Nondestructive testing; Residual stress; Room temperature; Speckle patterns; Strain gauges; Stress analysis; Stress relaxation; Tensile stress; Tensile tests; Thermal expansion; Thermal properties; Visualization; residual stress; optical interferometry; thermal expansion; elasticity; non-destructive testing
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma15186330

This paper deals with a non-destructive analysis of residual stress through the visualization of deformation behaviors induced by a local spot heating. Deformation was applied to the surface of an aluminum alloy with an infrared spot laser. The heating process is non-contact, and the applied strain is reversible in the range of room temperature to approximately +10 °C. The specimen was initially pulled up to elastic tensile stress using a tensile test machine under the assumption that the material was subject to the tensile residual stress. The relaxation behaviors of the applied strain under tensile stress conditions were evaluated using contact and non-contact methods, i.e., two strain gauges (the contact method) and a two-dimensional electronic speckle pattern interferometer (non-contact method). The results are discussed based on the stress dependencies of the thermal expansion coefficient and the elasticity of the materials.