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Ultrasonic infrared thermography is a rapid and informative method of nondestructive testing, used to inspect materials and products in aviation and rocket and space industries. High-power piezoelectric emitters stimulate various materials by ultrasound and help revealing hidden flaws by local temperature changes, which can amount to tens of degrees. The possibility of optimizing the procedure of ultrasonic infrared thermography by choosing the frequency of acoustic waves so as to match the frequencies of local resonances of defects of different sizes has been investigated.

The quality control of composite materials remains an important topic of research in nondestructive testing (NDT) of modern materials, in particular, the ones intended for aerospace industry. Over the last decade, there has been a noticeable increase in interest to the ultrasonic stimulation of tested materials and analysis of dynamic temperature distributions. This method is commonly implemented with two techniques, viz. high-power stimulation at a fixed acoustic-signal frequency and low-power resonant ultrasonic stimulation. Results are provided on comparing the above ultrasonic NDT methods using the example of an impact damage in a graphite epoxy-filled composite. The comparison is made based on the criteria of temperature signals, revealed flawed zone, and productivity of testing.

Ultrasound-excited vibrothermography (VT) is a newly developed version of InfraRed (IR) thermographic Non-Destructive Testing (NDT), but the relation between the defect signal and mechanical parameters is fuzzy due to the complexity of thermo-mechanical coupling and the interaction effects of multiple factors, so the design of operation conditions of VT is highly-dependent on the experience of operators. In order to reveal the relations of the defect signal vs. the mechanical parameters, and to enable the optimisation of operation conditions, a mathematical model was presented to simulate the heat generation and heat transfer that occur during VT. The heat power produced in a crack and the temperature increase at the crack area were solved by an analytical approach. The function of the temperature increase at the crack area vs. the mechanical parameters including the damp, mass, stiffness, amplitude and frequency of the stimulation force, friction coefficient and normal force in crack faces, excitation du...

Solid rocket motors (SRMs) are key components of missiles, space rockets and shuttles. In order to prevent their combustion chamber cases from being damaged by high-temperature and high-pressure gas, they must be protected by special thermal insulation layers. Disbonds, or poor bonding in the adhesion interfaces often appear during manufacture because of technological reasons, thus possibly causing catastrophic failure of space vehicles when in operation. Pulsed IR thermography (PIRT) has been used successfully for detecting defects in aero space components due to its high productivity, one-sided access and safe exploitation. This paper describes some results of applying PIRT to the inspection of the thermal insulation of SRM cases. Particular emphasis is laid on the development of some novel approaches based on the correlation technique.