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The purpose of this study has been to develop a multivariate model for predicting body fat mass in women by using the technique of infrared (IR) thermography. Sixty-nine healthy women, aged from 16...

Three nondestructive testing techniques, namely, optically- and ultrasonically stimulated infrared thermography, ultrasonic laser vibrometry and laser ultrasonics, have been comparatively investiga...

The use of infrared thermography for quantitative evaluation of water ingress in aviation honeycomb cells is discussed. Numerical modelling has been performed by analysing a 3D panel model where water fully or partially occupies honeycomb cells. Calculation of several test cases has allowed better understanding of how the thickness of the water layer affects surface temperature anomalies and times of their appearance in active one-sided thermal tests. Experimental results have been obtained on both reference samples and real honeycomb panels.

This paper presents a brief history and the current status of research at the Thermal Nondestructive Testing Laboratory of Tomsk Polytechnic University (TPU), Russia. The emphasis of the laboratory research is advanced modelling (analytical and numerical) and data processing, including Fourier and wavelet transform, neural networks, correlation analysis, dynamic thermal tomography, and other methods of thermal NDT. This paper describes experimental tests, practical applications in aviation and energy audits, as well as areas of future research.

A thermo mechanical problem of internal friction in zero-thickness defects is numerically solved, and the theoretical predictions are qualitatively compared with experimental data. Some examples of impact damage characterization by applying both ultrasonic and optical material stimulation are presented.

The first practical attempts of sensing our world in the infrared spectrum were undertaken in the nineteenth century. One of the first implementations of the active thermal non-destructive testing (TNDT) was the inspection of Polaris rocket motor cases in 1965 but by the end of the 1970s applications of IR thermography inspired by successful developments of IR technology in military were still rather qualitative thus preventing the progressive competition of TNDT with other inspection techniques. A new level of TNDT was achieved after the wider use of elements of the heat conduction theory. Nowadays, IR thermographic diagnostics and TNDT represent mature high-technology fields which combine achievements in the understanding of heat conduction, material science, IR technology and computer data processing. The high interest to the IR/thermal inspection technique is related to its universal character, high testing productivity and in-service safety. The purpose of this review is to briefly review the basics ...

The goal of this article is to demonstrate that, since IR imaging radiometers are not very efficient for accurate temperature measurement, IR thermographic estimates of heat losses from buildings may be confusing.

Theoretical and experimental results for determining thermal diffusivity components in anisotropic Carbon Fiber Reinforced Plastic laminates up to 5 mm thick are presented. The effectiveness of the theory is evaluated by using a 3D numerical model. IR thermographic implementation of the Parker's technique has been used for determining transverse diffusivity. Both spot- and slit-mask techniques have been applied for analyzing thermal diffusivity components.

An airborne laser IR thermographic system intended for remote gas detection is described. The system involves three channels of which one is active and two are passive. The active channel includes a 15 mW tunable laser diode illuminating the ground surface with 1 ms pulses of IR radiation at the wavelength of 1650 nm. The system sensitivity by the laser channel is about 100 ppm*m at 100 m (by methane). The two passive channels allow visualizing the ground surface in both the visual and mid-IR wavelength. The system has passed on-flight testing in cooperation with some Russian gas transportation companies.

This paper presents the analysis of classical heat conduction solutions applied to materials characterization. The formulas for parametric derivatives are obtained and illustrated with plentiful graphics to demonstrate the evolution of the relative sensitivity functions in time. The potential of using both front-surface and rear-surface solutions for determining material thermal properties, sample thickness and surface heat exchange parameters is discussed. The roots of the well-known transcendent equation for a non-adiabatic plate are approximated in a polynomial form. Some practical applications of the proposed formulas are reported.

Infrared thermographic inspection of water in aviation honeycomb panels is a wellknown technique. The hidden water can be detected due to its high thermal capacity that makes temperatures changes slow. A transient thermal regime can be realized by using external heaters or natural heating by the ambient. The paper describes some quantitative aspects of the water detection problem. The presented simulation results have been obtained by analyzing a one-dimensional model of a multi-layer plate where the ice-to-water phase transformation takes place. Some experimental results of inspecting Russian airplanes are also presented.

Building infrared thermography is a well-established but still qualitative technique that is used mostly for detecting insulation deficiencies, airleaks, moist areas, and thermal bridges in envelopes. Characterization of buried defects requires replacing steady-state thermography with a transient technique. It is proposed to borrow for this purpose the inspection methodology developed in the thermal nondestructive evaluation of materials. This methodology is based on recording the image sequence in both the heating and cooling stages, with the thermal stimulus being delivered onto the surface with a Dirac, square, or harmonic heat pulse. The dedicated image treatment allows the substitution of a sequence of any length with a pair of images called the “maxigram” and “timegram.” These images contain information needed for the characterization of defects. Some explicit inversion formulas discussed in the paper enable the determination of defect depth and thermal resistance. The proposed approach is illustrated with experimental results. Evaluation of internal corrosion in concrete and detection of underplaster delaminations are reported.