Optimizing the Inversion Protocol to Determine the Geometry of Vertical Cracks from Lock-in Vibrothermography

Castelo, A.; Mendioroz, A.; Celorrio, R.; Salazar, A.

doi:10.1007/s10921-016-0381-5

Cited by 21 publications

(29 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Active thermography implies the control of the energy, such as start time, duration, amount of energy delivered, and frequency for the purposes of inspection. Examples of active thermography heat sources are flash lamp, quartz lamp, eddy current, microwave, and ultrasound [ 9 , 10 , 11 , 12 , 13 ]. Passive thermography implies no control of the applied energy such as the sun, hot air, moisture evaporation, and structural loading.…”

Section: Introductionmentioning

confidence: 99%

Detection and Characterization of Damage in Quasi-Static Loaded Composite Structures Using Passive Thermography

Zalameda

Winfree

2018

Sensors

View full text Add to dashboard Cite

Real-time nondestructive evaluation is critical during composites load testing. Of particular importance is the real time measurement of damage onset, growth, and ultimate failure. When newly formed damage is detected, the loading is stopped for further detailed characterization using ultrasound inspections or X-ray computed tomography. This detailed inspection data are used to document failure modes and ultimately validate damage prediction models. Passive thermography is used to monitor heating from damage formation in a hat-stiffened woven graphite epoxy composite panel during quasi-static seven-point load testing. Data processing techniques are presented that enable detection of the small transient thermographic signals resulting from damage formation in real time. It has been observed that the temperature rise due to damage formation at the surface is composed of two thermal responses. The first response is instantaneous and conforms to the shape of the damage. This heating is most likely due to irreversible thermoelastic, plastic deformation, and microstructural heating. The second response is a transient increase in temperature due to mechanical heating at the interface of failure. Two-dimensional multi-layered thermal simulations based on quadrupole method are used to investigate the thermal responses. In particular, the instantaneous response is used as the transient response start time to determine damage depth. The passive thermography measurement results are compared to ultrasonic measurements for validation.

show abstract

Section: Introductionmentioning

confidence: 99%

Detection and Characterization of Damage in Quasi-Static Loaded Composite Structures Using Passive Thermography

Zalameda

Winfree

2018

Sensors

View full text Add to dashboard Cite

show abstract

“…UST (also known as thermosonics, sonic IR or vibro-thermography) is an alternative means of thermography that involves the generation of powerful vibrations in a test piece to cause frictional heating at crack surfaces. An IR camera with temperature resolution ranging between 20 and 40 mK is usually used to measure the frictional heating on the sample’s surface [ 97 , 98 , 99 ]. Figure 11 shows the experimental set-up for thermosonics.…”

Section: Ultrasonic Stimulated Thermographymentioning

confidence: 99%

“…Renshaw et al [ 108 ] have shown that heat generation in damage regions during a thermosonics experiment is mainly due to three different mechanisms: (i) frictional rubbing of contact regions of damage interfaces; (ii) plastic deformations during crack or damage growth that generate heat in the plastic zone surrounding these areas; and (iii) viscoelastic losses that generate significant heat in regions of stress concentration (i.e., around delaminations and other defects). Polimeno et al [ 99 ] developed a compact thermosonics inspection system with a microbolometer array camera to detect artificial delamination (i.e., an embedded Teflon patch) in composite materials. The authors used a parameter, known as Heating Index [ 109 ], to predict the vibration level in the presence of vibrations governed by “acoustic chaos”.…”

Section: Ultrasonic Stimulated Thermographymentioning

confidence: 99%

Recent Advances in Active Infrared Thermography for Non-Destructive Testing of Aerospace Components

Ciampa

Mahmoodi

Pinto

et al. 2018

Sensors

352

185

View full text Add to dashboard Cite

Active infrared thermography is a fast and accurate non-destructive evaluation technique that is of particular relevance to the aerospace industry for the inspection of aircraft and helicopters’ primary and secondary structures, aero-engine parts, spacecraft components and its subsystems. This review provides an exhaustive summary of most recent active thermographic methods used for aerospace applications according to their physical principle and thermal excitation sources. Besides traditional optically stimulated thermography, which uses external optical radiation such as flashes, heaters and laser systems, novel hybrid thermographic techniques are also investigated. These include ultrasonic stimulated thermography, which uses ultrasonic waves and the local damage resonance effect to enhance the reliability and sensitivity to micro-cracks, eddy current stimulated thermography, which uses cost-effective eddy current excitation to generate induction heating, and microwave thermography, which uses electromagnetic radiation at the microwave frequency bands to provide rapid detection of cracks and delamination. All these techniques are here analysed and numerous examples are provided for different damage scenarios and aerospace components in order to identify the strength and limitations of each thermographic technique. Moreover, alternative strategies to current external thermal excitation sources, here named as material-based thermography methods, are examined in this paper. These novel thermographic techniques rely on thermoresistive internal heating and offer a fast, low power, accurate and reliable assessment of damage in aerospace composites.

show abstract

“…In recent years, infrared thermography with ultrasonic excitation has proven to be a very useful tool to characterize the dimensions and depth of vertical cracks, both in lock-in [1] and burst regimes [2]. In this technique, when the sample is excited with ultrasounds the defect behaves as a heat source, due to the local conversion of mechanical into thermal energy.…”

Section: Introductionmentioning

confidence: 99%

Characterization of slanted buried planar heat sources using time domain Infrared Thermography

Mendioroz¹,

Salazar²,

Martínez³

et al. 2018

Proceedings of the 2018 International Conference on Quantitative InfraRed Thermography

Self Cite

View full text Add to dashboard Cite

We address the characterization of planar inner defects of any inclination, using infrared thermography (IRT) with any kind of excitation that turns the defect into a heat source (ultrasonic or eddy current). First, we calculate the surface temperature distribution. Then, we present multi-parametric fittings (dimensions, depth and inclination) of noisy synthetic data to characterize the defect. Finally, we prepare 3D printed plastic parallelepiped samples containing graphite and copper slabs that are excited optically and inductively, respectively. The fittings of the data to the model confirm the ability of IRT to characterize planar defects with any inclination.

show abstract

Optimizing the Inversion Protocol to Determine the Geometry of Vertical Cracks from Lock-in Vibrothermography

Cited by 21 publications

References 30 publications

Detection and Characterization of Damage in Quasi-Static Loaded Composite Structures Using Passive Thermography

Detection and Characterization of Damage in Quasi-Static Loaded Composite Structures Using Passive Thermography

Recent Advances in Active Infrared Thermography for Non-Destructive Testing of Aerospace Components

Characterization of slanted buried planar heat sources using time domain Infrared Thermography

Contact Info

Product

Resources

About