Composite materials are employed in industry at a high rate, and the demand is increasing. Recently, prepreg carbon and aramid-carbon composite structures, when compared to carbon fiber reinforced polymer composites, have attracted increasing attention due to their better impact damage resistance. In order to characterize the material, impact test according to EN DIN 6038 was carried out including infrared acquisition of impact. Based on the cooled MW InSb detector IR camera, the spread of damage was observed during impact test.
{"title":"Thermal analysis of impact damage of prepreg composite materials","authors":"P. Bagavac, L. Krstulović-Opara, Ž. Domazet","doi":"10.21611/qirt.2020.090","DOIUrl":"https://doi.org/10.21611/qirt.2020.090","url":null,"abstract":"Composite materials are employed in industry at a high rate, and the demand is increasing. Recently, prepreg carbon and aramid-carbon composite structures, when compared to carbon fiber reinforced polymer composites, have attracted increasing attention due to their better impact damage resistance. In order to characterize the material, impact test according to EN DIN 6038 was carried out including infrared acquisition of impact. Based on the cooled MW InSb detector IR camera, the spread of damage was observed during impact test.","PeriodicalId":191498,"journal":{"name":"Proceedings of the 2020 International Conference on Quantitative InfraRed Thermography","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126966758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Švantner, L. Muzika, A. Moskovchenko, Š. Houdková, Petra Frková
Flash-pulse thermography is a method for a detection of discontinuities or inhomogeneities in materials at their surface. It is based on an excitation of an inspected sample by a short pulse and analysis of its thermal response. An application of flash-pulse thermography for a quantitative inspection of thickness differences of thermally sprayed coatings is introduced in this contribution. Requirements for a synchronization of thermal response recording and data smoothing precision are described. Signal derivative, pulse-phase and time power-transformation (P-function) methods for an evaluation of the thermographic records are presented. Procedure and results of the inspection are demonstrated on HVOF, TWAS and flame sprayed coatings. A comparison of the method showed that the P-function method is the most suitable for a quantification of coating thickness differences. Some characteristic of the method are demonstrated by numerical computation.
{"title":"Quantitative inspection of thickness of thermally sprayed coatings by flash pulse thermographic method","authors":"M. Švantner, L. Muzika, A. Moskovchenko, Š. Houdková, Petra Frková","doi":"10.21611/qirt.2020.042","DOIUrl":"https://doi.org/10.21611/qirt.2020.042","url":null,"abstract":"Flash-pulse thermography is a method for a detection of discontinuities or inhomogeneities in materials at their surface. It is based on an excitation of an inspected sample by a short pulse and analysis of its thermal response. An application of flash-pulse thermography for a quantitative inspection of thickness differences of thermally sprayed coatings is introduced in this contribution. Requirements for a synchronization of thermal response recording and data smoothing precision are described. Signal derivative, pulse-phase and time power-transformation (P-function) methods for an evaluation of the thermographic records are presented. Procedure and results of the inspection are demonstrated on HVOF, TWAS and flame sprayed coatings. A comparison of the method showed that the P-function method is the most suitable for a quantification of coating thickness differences. Some characteristic of the method are demonstrated by numerical computation.","PeriodicalId":191498,"journal":{"name":"Proceedings of the 2020 International Conference on Quantitative InfraRed Thermography","volume":"218 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131463869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Poelman, S. Hedayatrasa, J. Segers, W. Paepegem, M. Kersemans
Flash thermography is a promising non-destructive testing technique for the inspection of composite components. However, non-uniform heating, measurement noise and lateral heat diffusion complicate the interpretation of thermographic measurements. In order to overcome these difficulties, a novel baseline-free processing technique called ‘Multi-Scale Gapped Smoothing Algorithm’ is presented. This algorithm constructs a damage map directly from the measured data, in which an (almost) zero-reference background is obtained, and where measurement noise and excitation non-uniformity are effectively suppressed. The efficiency of the proposed technique is evaluated and confirmed through synthetic data and experimental results of a carbon fiber reinforced polymer with various artificial defects.
{"title":"A robust multi-scale gapped smoothing algorithm for baseline-free damage mapping from raw thermal images in flash thermography","authors":"G. Poelman, S. Hedayatrasa, J. Segers, W. Paepegem, M. Kersemans","doi":"10.21611/QIRT.2020.020","DOIUrl":"https://doi.org/10.21611/QIRT.2020.020","url":null,"abstract":"Flash thermography is a promising non-destructive testing technique for the inspection of composite components. However, non-uniform heating, measurement noise and lateral heat diffusion complicate the interpretation of thermographic measurements. In order to overcome these difficulties, a novel baseline-free processing technique called ‘Multi-Scale Gapped Smoothing Algorithm’ is presented. This algorithm constructs a damage map directly from the measured data, in which an (almost) zero-reference background is obtained, and where measurement noise and excitation non-uniformity are effectively suppressed. The efficiency of the proposed technique is evaluated and confirmed through synthetic data and experimental results of a carbon fiber reinforced polymer with various artificial defects.","PeriodicalId":191498,"journal":{"name":"Proceedings of the 2020 International Conference on Quantitative InfraRed Thermography","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114543291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Correlation between the reading of a thermal imaging camera and the focus of an electronic component thermogram","authors":"K. Dziarski","doi":"10.21611/qirt.2020.029","DOIUrl":"https://doi.org/10.21611/qirt.2020.029","url":null,"abstract":"","PeriodicalId":191498,"journal":{"name":"Proceedings of the 2020 International Conference on Quantitative InfraRed Thermography","volume":"48 22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117254120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Diagnostic accuracy in thermographic imaging for granulation of uninfected diabetic ulcers.","authors":"R. D, C. J, Benites-Castillo S","doi":"10.21611/qirt.2020.110","DOIUrl":"https://doi.org/10.21611/qirt.2020.110","url":null,"abstract":"","PeriodicalId":191498,"journal":{"name":"Proceedings of the 2020 International Conference on Quantitative InfraRed Thermography","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121374323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Aouali, S. Chevalier, A. Sommier, J. Batsale, C. Pradère
Plasma torches are a type of source that generates very high temperatures. They are mainly used in surface treatment applications and ultimate waste treatment. The knowledge of the temperature field in plasma torches is of prime interest for researchers and industry to model and optimize the torch design. First experiments to measure the plasma torch temperature were reported by J.-L. Gardarein et al. [1] using a probe with a thermocouple directly inserted into the plasma. This first measurement led to the knowledge of plasma heat flux, but it was an intrusive method which gives only a single average value. To move forward, researches at I2M are conducted in collaboration with Europlasma to thermally and chemically characterize plasma torches with the end goal of 3D non-contact heat flux and temperature field measurements. To ensure the previous objective, radiometric techniques are developed which provide adequate means to measure contactless temperature [2]. This temperature can be deduced from the luminance measured using an IR camera if the emissivity of the body is known [3]. In flame measurements, the assumption of thermal equilibrium is generally done [4] which makes the cartography of the emissivity, ε, to be equal to the absorptivity, α. Thus, by measuring the transmissivity,τ, of an IR beam through the flame, one can deduce the absorptivity, where α = 1 − τ in semi-transparent medium, and therefore obtain ε. This methodology is validated at the lab scale using a small flame generated by a burner, an IR source and camera. In Figure 1, the experimental setup to measure the flame temperature is depicted. Three simultaneous acquisitions are made using a shutter synchronized with the camera: (1) the IR source beam alone, (2) the IR source beam + the proper emission of the flame, and (3) the proper emission of the flame alone. From this 3-images method, the total hemispheric transmissivity τ is measured. This result is presented is Figure 2(a) where the thermo-dependence of the transmittivity in the flame is observed. The transmittivity ranges from 0.16 to 0.4, which leads to an emissivity range between 1 and 0.84 (Figure 2(b)). As expected, the flame differs from the black body (emissivity of 1) which has justified the need of emissivity measurements to obtain the true flame temperature from an IR camera. This thermodependency of emissivity is expected to be strengthened in plasma torches which reach 5000 K (about 4-5 time hotter than the flame used in this experiments). In the oral presentation, this 3-images methodology will be presented in details and results of flame temperature measurements will be reported. Fig. 1. Set-up used for the 3-images method 10.21611/qirt.2020.085 15 Quantitative InfraRed Thermography Conference, 6 – 10 July 2020, Porto, Portugal 2 Fig. 2. (a). Cartography of Transmissivity, (b). Cartography of Emissivity
{"title":"Absolute Temperature Field Measurements in Flames based on Infrared ThermoSpectroscopic Imaging","authors":"A. Aouali, S. Chevalier, A. Sommier, J. Batsale, C. Pradère","doi":"10.21611/qirt.2020.085","DOIUrl":"https://doi.org/10.21611/qirt.2020.085","url":null,"abstract":"Plasma torches are a type of source that generates very high temperatures. They are mainly used in surface treatment applications and ultimate waste treatment. The knowledge of the temperature field in plasma torches is of prime interest for researchers and industry to model and optimize the torch design. First experiments to measure the plasma torch temperature were reported by J.-L. Gardarein et al. [1] using a probe with a thermocouple directly inserted into the plasma. This first measurement led to the knowledge of plasma heat flux, but it was an intrusive method which gives only a single average value. To move forward, researches at I2M are conducted in collaboration with Europlasma to thermally and chemically characterize plasma torches with the end goal of 3D non-contact heat flux and temperature field measurements. To ensure the previous objective, radiometric techniques are developed which provide adequate means to measure contactless temperature [2]. This temperature can be deduced from the luminance measured using an IR camera if the emissivity of the body is known [3]. In flame measurements, the assumption of thermal equilibrium is generally done [4] which makes the cartography of the emissivity, ε, to be equal to the absorptivity, α. Thus, by measuring the transmissivity,τ, of an IR beam through the flame, one can deduce the absorptivity, where α = 1 − τ in semi-transparent medium, and therefore obtain ε. This methodology is validated at the lab scale using a small flame generated by a burner, an IR source and camera. In Figure 1, the experimental setup to measure the flame temperature is depicted. Three simultaneous acquisitions are made using a shutter synchronized with the camera: (1) the IR source beam alone, (2) the IR source beam + the proper emission of the flame, and (3) the proper emission of the flame alone. From this 3-images method, the total hemispheric transmissivity τ is measured. This result is presented is Figure 2(a) where the thermo-dependence of the transmittivity in the flame is observed. The transmittivity ranges from 0.16 to 0.4, which leads to an emissivity range between 1 and 0.84 (Figure 2(b)). As expected, the flame differs from the black body (emissivity of 1) which has justified the need of emissivity measurements to obtain the true flame temperature from an IR camera. This thermodependency of emissivity is expected to be strengthened in plasma torches which reach 5000 K (about 4-5 time hotter than the flame used in this experiments). In the oral presentation, this 3-images methodology will be presented in details and results of flame temperature measurements will be reported. Fig. 1. Set-up used for the 3-images method 10.21611/qirt.2020.085 15 Quantitative InfraRed Thermography Conference, 6 – 10 July 2020, Porto, Portugal 2 Fig. 2. (a). Cartography of Transmissivity, (b). Cartography of Emissivity","PeriodicalId":191498,"journal":{"name":"Proceedings of the 2020 International Conference on Quantitative InfraRed Thermography","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115985459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Rodríguez-Aseguinolaza, J. González, R. Celorrio, A. Mendioroz, A. Salazar
A new numerical model based on discontinuous Galerkin Finite Element Methods for laser spot lock-in thermopgraphy has been developed able to characterize very narrow cracks in materials, difficult to quantify by alternative numerical methods. It has also been validated by means of experimental results from a wide variety of cracks in terms of size, width, depth and crack orientation angle. Overall, the obtained results indicate a very good agreement with experiments maintaining a satisfactory accuracy and improved computational economy.
{"title":"Discontinuous finite element numerical modelling for infrared thermographic crack characterization","authors":"J. Rodríguez-Aseguinolaza, J. González, R. Celorrio, A. Mendioroz, A. Salazar","doi":"10.21611/qirt.2020.068","DOIUrl":"https://doi.org/10.21611/qirt.2020.068","url":null,"abstract":"A new numerical model based on discontinuous Galerkin Finite Element Methods for laser spot lock-in thermopgraphy has been developed able to characterize very narrow cracks in materials, difficult to quantify by alternative numerical methods. It has also been validated by means of experimental results from a wide variety of cracks in terms of size, width, depth and crack orientation angle. Overall, the obtained results indicate a very good agreement with experiments maintaining a satisfactory accuracy and improved computational economy.","PeriodicalId":191498,"journal":{"name":"Proceedings of the 2020 International Conference on Quantitative InfraRed Thermography","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132567861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Coating thickness (thermal barrier coatings, anticorrosion paints, etc.) can influence its properties and therefore the thickness is often measured in industrial application. This contribution describes fast areal thickness estimation based on flash pulse thermography. Specimens sprayed by a black paint on AISI 304 substrates were used for a demonstration of the thickness estimation. Two different types of post-processing and thickness estimation were used: functional calibration with FFT (phase) and analytical model. Both procedures were compared and both provided satisfactory results with maximum error of thickness estimation less than 10 %. Advantages and disadvantages of proposed techniques are discussed.
{"title":"Analysis of paint thickness based on flash pulse thermography","authors":"L. Muzika, M. Švantner","doi":"10.21611/qirt.2020.040","DOIUrl":"https://doi.org/10.21611/qirt.2020.040","url":null,"abstract":"Coating thickness (thermal barrier coatings, anticorrosion paints, etc.) can influence its properties and therefore the thickness is often measured in industrial application. This contribution describes fast areal thickness estimation based on flash pulse thermography. Specimens sprayed by a black paint on AISI 304 substrates were used for a demonstration of the thickness estimation. Two different types of post-processing and thickness estimation were used: functional calibration with FFT (phase) and analytical model. Both procedures were compared and both provided satisfactory results with maximum error of thickness estimation less than 10 %. Advantages and disadvantages of proposed techniques are discussed.","PeriodicalId":191498,"journal":{"name":"Proceedings of the 2020 International Conference on Quantitative InfraRed Thermography","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121035957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：