Search results for "infrared thermography"
showing 10 items of 33 documents
IMPLEMENTAZIONE DI TECNICHE NDT DI TERMOGRAFIA AD INFRAROSSI SU PANNELLI IN COMPOSITO GRP PER APPLICAZIONI NAUTICHE
2010
Il presente lavoro descrive l’implementazione di due tecniche di termografia attiva ad infrarossi per il controllo non distruttivo (IRNDT) di delaminazioni sub-superficiali su pannelli in composito (GRP) di grosso spessore, tipicamente impiegati per uso navale. Si è in particolare fatto uso di attrezzature a basso costo consistenti in comuni lampade alogene a bassa potenza come sorgenti di calore esterne, ed una termocamera ad infrarossi a singolo sensore a bassa risoluzione termica e basso frame rate. Le due tecniche implementate sono la Pulsed Thermography (PT) ed una nuova variante di Lock-In Thermography denominata Pulse-Modulated Lock-In Thermography (PMLT), basata sull’analisi in freq…
IMPLEMENTAZIONE DI TECNICHE DI TERMOGRAFIA ATTIVA IRNDT SU COMPOSITI GRP MEDIANTE LA DEPOSIZIONE DI IMPULSI TERMICI DI LUNGA DURATA
2011
Nel presente lavoro viene analizzata l’implementazione di tecniche attive di termografia ad infrarossi per analisi NDT su pannelli in composito. In particolare si propone l’uso di lampade alogene come sorgente di calore esterna, le quali richiedono tempi di accensione dell’ordine di diversi secondi al fine di depositare efficaci quantità di calore. Si discutono quindi le problematiche connesse all’implementazione di tecniche di Transient Thermography e di Lock-In Thermography in presenza di tempi lunghi di deposizione di calore. Viene implementata una tecnica di modulazione della deposizione di calore mediante treni di onde quadre di lunga durata (PMLT - Pulse Modulated Lock-In Thermography…
Lock-In Signal Post-Processing Techniques in Infra-Red Thermography for Materials Structural Evaluation
2013
This paper describes the potential of off-line thermographic signal processing by means of Lock-In Correlation algorithms, in order to implement structural health monitoring and stress analysis techniques. Thermal datasets acquired by infrared thermocameras are locked-in and correlated numerically with opportune reference signals, and amplitude and phase values of various harmonics retrieved by means of a Fast Fourier Transform and time averaging based filtering. This information is then processed for NDT defect probing and for evaluating the Thermoelastic Effect induced temperature changes. Two case studies in particular are discussed, implementing the proposed signal lock-in processing: a…
ARCHITECTURAL SURVEY TECHNIQUES FOR DEGRADATION DIAGNOSTICS. AN APPLICATION FOR THE CULTURAL HERITAGE
2021
Abstract. The great technological development in recent years in the field of architectural survey has made possible increasingly expeditious and less invasive investigations with the aim of acquiring a series of data related to the asset and fundamental for the protection of cultural heritage. In addition, the synergy between the various techniques represents an added value able, not only, to fill possible gaps and lacks arising from application limits of the instruments, but also to enhance the peculiarities of the same. This paper presents an integrated survey activity (range-based, image-based and IR thermography techniques) aimed at applying the combination and collaboration of multipl…
Thermal NDT of glass reinforced composite panels for naval applications by means of a linear infrared scanner
2009
The work describes the development and application of a low cost Thermal NDT set-up to investigate the influence of delamination defects on thick glass fibre reinforced composite laminates simulating typical hull monolithic GRP panels. Two active thermographic techniques have been implemented in particular: a pulsed thermography and a step heating scheme. A 12 mm thick cross-ply panel has been manufactured and delamination defects simulated in two different ways: by embedding patches of folded Teflon sheets, and by drilling flat bottomed back holes. A number of defects was then positioned at three different depths form the scanned surfaces, measuring ¼, ½ and ¾ of the laminate thickness. A …
Geophysical surveys for the restoration of Branciforte Palace in Palermo
2019
A multi-methodological and non-invasive geophysical study has been carried out in order to support the restoration project of the historic Branciforte Palace in Palermo. Ground Penetrating Radar profiles and an Electrical Resistivity Tomography ERT, carried out on the floor of the stable of the Palace, allowed to evaluate in detail the state of consolidation of the subsoil, in correspondence of a double row of marble columns, some of which were affected by differential subsidence. These columns have been investigated by means of Ultrasonic Tomography to verify their state of degradation. Moreover Infrared Thermography images of the internal and external walls and of the vaults highlighted d…
The infrared thermography control of the laser welding of amourphous polymers
2008
International audience; In laser welding technique, a real-time control of temperature distribution inside the irradiated materials is essential when attempting to optimize the process. For all laser welding methods that operate by the transmission principle, the difficulty of recording the developed temperature at the interface derives from the fact that materials to be welded are in contact throughout the entire process. In the present study, in order to overcome this issue, a contact-free method such the infrared thermography is used for surface temperature measurement. Corroborating this data with a numerical simulation of the temperature field evolution inside the components, an assess…
Thermomechanical Behavior of Beams Covered with Viscoelastic Patches
2018
International audience; Infrared thermography is a non-destructive test method based on infrared measurement that provides a luminance map of the thermal scene observed, converting to temperature. The thermographic study allows a surface observation of the thermal effects in order to display the result as a film of the temperature distribution [1]. The present study focuses on the detection of volumetric energy sources in beams covered by viscoelastic patches.
Reproducibility of Skin Temperature Response after Cold Stress Test Using the Game Ready System: Preliminary Study
2021
The objective of this preliminary study was to determine the reproducibility of lower limbs skin temperature after cold stress test using the Game Ready system. Skin temperature of fourteen participants was measured before and after cold stress test using the Game Ready system and it was repeated the protocol in four times: at 9:00, at 11:00, at 19:00, and at 9:00 h of the posterior day. To assess skin temperature recovery after cold stress test, a logarithmic equation for each region was calculated, and constant (β0) and slope (β1) coefficients were obtained. Intraclass correlation coefficient (ICC), standard error (SE), and within-subject coefficient of variation (CV) were determined. No …
Thermographic imaging in sports and exercise medicine:a Delphi study and consensus statement on the measurement of human skin temperature
2017
© 2017 Elsevier Ltd The importance of using infrared thermography (IRT) to assess skin temperature (t sk ) is increasing in clinical settings. Recently, its use has been increasing in sports and exercise medicine; however, no consensus guideline exists to address the methods for collecting data in such situations. The aim of this study was to develop a checklist for the collection of t sk using IRT in sports and exercise medicine. We carried out a Delphi study to set a checklist based on consensus agreement from leading experts in the field. Panelists (n = 24) representing the areas of sport science (n = 8; 33%), physiology (n = 7; 29%), physiotherapy (n = 3; 13%) and medicine (n = 6; 25%…