Infrared Thermography Research

The 9m-long CX-100 composite wind turbine blade at UCSD’s Powell Research Laboratories. 

The infrared thermographic equipment next to the CX-100 blade

Statistically enhanced infrared thermography for the detection of delaminations in composite panels

Results of lock-in thermography for the detection of delaminations in the CX-100 blade 

“Virtual Heat Source” model for quantitative defect detection by IR thermography

Results of Virtual Heat Source model for quantification of defects in composite panel.

Delamination detection in composites via TSR (1st derivative image)

Impact damage detection in hockey sticks via TSR (2nd derivative images)

Funding:

Synopsis:

Ongoing research in the area of Infrared Thermography is aimed at gaining a better understanding of the heat flow through the test material, particularly composite materials. Enhancements to the Infrared Thermography technique are being made to detect and quantify structural flaws. Such enhancements include: (a) quantitative, 3-D thermal diffusion models for isotropic and anisotropic materials to relate an internal defect to the surface temperature profile, (b) statistical analysis of the infrared images to increase defect contrast and minimize false positives, (3) utilization of the lock-in thermography technique to penetrate  thick composites, and (4) utilization of Thermographic Signal Reconstruction (TSR) techniques to improve image contrast. These aspects have been applied to various composite structures and particularly to composite wind turbine blades and aircraft panels.

Selected Publications:

Manohar, A. and Lanza di Scalea, F., “Wavelet-aided Multivariate Outlier Analysis to Enhance Defect Contrast in Thermal Images,” Experimental Techniques, 38(1), pp. 28-37, 2014.

Manohar, A. and Lanza di Scalea, F., “Detection of Defects In Wind Turbine Composite Blades Using Statistically-Enhanced Lock-In Thermography,” Structural Health Monitoring International Journal, Special Issue on Noncontact Measurement Technologies, 12(5-6), pp. 566-574, 2014.

Manohar, A. and Lanza di Scalea, F., “Modeling 3-D Heat Flow Interaction with Defects in Composite Materials for Infrared Thermography,” NDT&E International Journal, 66, pp. 1-7, 2014.

Manohar A. and Lanza di Scalea, F., “Determination of Defect Depth and Size Using Virtual Heat Sources in Pulsed Infrared Thermography,” Experimental Mechanics, 53(4), pp. 661-671, 2013.

Manohar, A. and Lanza di Scalea, F., “Modeling Heat Flow Interaction With Defects In Composite Materials Using Virtual Heat Sources In Pulsed Thermography,” Proceedings of the 2013 ASME International Mechanical Engineering Congress and Exposition (IMECE 2013), San Diego, CA, November 15-21, 2013.

Manohar, A. and Lanza di Scalea, F., “Defect Detection and Size Estimation in Composite Materials Using Infrared Thermography,” Proceedings of the SEM 2013 Annual Conference & Exposition on Experimental and Applied Mechanics, Lombard, IL, June 3-5, 2013.

Manohar, A., Tippmann, J., and Lanza di Scalea, F., “Localization Of Defects In Wind Turbine Blades And Depth Estimation Using Infrared Thermography,” Proceedings of SPIE (International Society for Optical Engineering) Smart Structures/NDE Annual International Symposium – Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems, M. Tomizuka, ed., San Diego, CA, March 11-15, Vol. 8345, 2012.

Tippmann, J., Manohar, A., and Lanza di Scalea, F., “Wind Turbine Blade Inspection Tests At UCSD”, Proceedings of SPIE (International Society for Optical Engineering) Smart Structures/NDE Annual International Symposium – Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems, M. Tomizuka, ed., San Diego, CA, March 11-15, Vol. 8345, 2012.