Infrared thermographic assessment of heat release phenomena in steel parts subjected to quasi-static deformation

• Published in: Measurement : journal of the International Measurement Confederation 2021-11, Vol.185, p.110117, Article 110117
• Main Authors: Moyseychik, E.A., Vavilov, V.P., Kuimova, M.V.
• Format: Article
• Language: English
• Subjects: Anomalies; Crack initiation; Deformation; Deformation heat release; Edge dislocations; Elastic deformation; Evaluation; Fracture; Heat transfer; Mechanical properties; Nondestructive testing; Passive infrared thermography; Plastic deformation; Quantitative analysis; Shear band; Shear bands; Static deformation; Steel; Steel part; Steel structures; Tension; Thermography
• ISSN: 0263-2241; 1873-412X
• DOI: 10.1016/j.measurement.2021.110117

•Appearance of shear bands is accompanied by temperature increase of about 4–12.5 °C.•Deformation in steel occurs at four stages including formation of elastic clusters.•Infrared thermography has proven that elastic clusters are separated by shear bands.•With growing width of shear bands, their temperature increases to critical values. The paper describes the mechanism of heat release during deformation and main features of passive infrared thermographic diagnostics of steel parts subjected to elastic, elastic–plastic and plastic deformation under quasi-static loading. A basic equation for evaluating temperature signals caused by quasi-static deformation is derived. It is stated that the evaluation of steel structures by passive thermal methods should be performed when the heat is generated by mechanical stresses appearing in structures subjected to mechanical loading. The analysis of the loading kinetics and temperature anomalies has shown that thermal nondestructive testing technique is a useful tool for determining stress state in steel structures during the initiation and evolution of fracture. It is shown that the quasi-static deformation of steel structures is accompanied by the formation of elastic clusters separated by shear bands, and the plastic deformation in shear bands causes heat release resulting in a temperature increase of 4–12.5 °C.