Stress monitoring and analysis using lock-in thermography

• Published in: Insight (Northampton) Vol. 52; no. 9; pp. 470 - 474
• Main Authors: George, S, Goravar, S, Mishra, D, Shyamsunder, M T, Sharma, P, Padmashree, G K, Kumar, P S, Bremond, P, Mukherjee, K
• Format: Journal Article
• Language: English
• Published: Northampton British Institute of Non-Destructive Testing 01.09.2010
• Subjects: Applied sciences; Composites; Exact sciences and technology; Forms of application and semi-finished materials; Fundamental areas of phenomenology (including applications); Industrial metrology. Testing; Measurement and testing methods; Mechanical engineering. Machine design; Physics; Polymer industry, paints, wood; Properties and testing; Solid mechanics; Structural and continuum mechanics; Technology of polymers; Testing and control; Resistance strain gauge; Infrared thermography; Thermal method; Stress wave; Modeling; Finite element method; Thermoelasticity; Thermal imaging; Non destructive test; Computer aided design; Dynamic load; Carbon fiber; Stress measurement
• ISSN: 1354-2575; 1754-4904
• DOI: 10.1784/insi.2010.52.9.470

An advanced non-destructive evaluation technique based on a thermal method and lock-in principles, known as thermoelastic stress analysis (TSA), is proposed for accurate stress measurements. Traditionally, strain gauges mounted on components of interest are used to measure stresses indirectly. In this paper, we describe the application of a thermoelastic stress analysis technique to a carbon-epoxy composite sample under dynamic loading to measure stresses. The advantages of this technique over strain gauges are described. The paper also describes methods for mapping of TSA results on CAD models and comparing the stresses with results obtained through finite element modelling.