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

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 degrees C.

Automated summary

This paper describes the mechanism of heat release during deformation and main features of passive infrared thermographic diagnostics of steel parts under quasi static loading. It derived a basic equation for evaluating temperature signals caused by quasi-static deformation. The analysis shows that thermal nondestructive testing technique is a useful tool for determining stress state in steel structures during fracture initiation and evolution.