In this paper, optical infrared thermography simulation using thermal wave imaging technique is performed to analyze the thermal characteristics of delamination defects. In this study, lock-in thermography(LIT) and pulsed thermography(PT) simulation was performed to analyze the samples of european traditional tiles with delamination defects, and the analytical modeler was developed through the ANSYS 19.2 transient thermal analysis tool. Applied sinusoidal heating with modulation frequency according to pulse heating and phase locking technique. The thermal response of the sample surface by heating was recorded and then data analysis was performed. The temperature gradient characteristics of each technique were compared, and phase angle was calculated for the LIT to analyze the parameters for the experiment setting. The simulation model was developed as a useful data for practical optical infrared thermography tests.

Crack in concrete surfaces is one of the earliest signs of decomposition of the essential structure and constant exposure will cause serious damage to the structure and environment. In most of the safety assessment and fracture mechanic applications proposed that these cracks and defects eventually will grow and will have potential lead to in-service failure. Crack in concrete surfaces is one of the earliest signs of decomposition of the essential structure and constant exposure will cause serious damage to the structure and environment. Currently, non-destructive methods are getting popular in the field of inspecting defects in structure and one of them in trends is that using the thermographic image to detect hidden effects. However, the accuracy of the thermal camera, also called resolution, is highly dependent on camera variables such as lens, detector, sensitivity etc. Also, the most important question that needs to be answered for this research is what happens to the image in fog, rain or other climatic conditions where the camera detects crack which exceptionally smaller than most thermographic applications detects. This paper investigates the accuracy of thermal images obtained by the thermal camera under various weather condition and aims at providing information about optimum choice of environmental condition where the more favorable thermal images can be obtained and increase survey reliability and accuracy of the analysis.

The purpose of this paper is to find an limitation to detect the defect of damaged asphalt pavement structures for infrared thermography. We use heat source of a natural light to detect the defect efficiently. The heat source was applied to the asphalt specimens. Four asphalt specimens were used: one was the asphalt containing depth of 1cm internal timber, two was the asphalt containing depth of 2cm internal void, Three was the asphalt containing depth of 3cm internal timber and four was not the asphalt containing internal timber. It was found that the depth of 3cm internal timber could be detected by this method. In addition, we used the image processing to make the damage zone displayed clear in the image obtained from the thermographic operation.

Clothing comfort indicates the comfortableness of the in varying environmental situations while wearing specific clothing. Various factors affect clothing comfort such as skin moisture perception and heat transmission characteristics via clothing; however, cool and warm touch are the most important factors (Kwon, Yi, & Sung,1999; Hong & Kim, 2007; Manshahia & Das, 2014). The thermal comfort of clothing is perceived through sensory receptors on the skin surface and is highly related to a cool and warm touch. An infrared thermography camera detects infrared-ray-form energy, a type of electromagnetic wave radiated from the subject's surface that assesses the intensity of radiant heat. The changing intensity then presents a real-time infrared thermal distribution using various colors. The advantages of an infrared thermography camera are the ability to use a non-contacting method to measure temperature distribution and analyze temperatures. Therefore, an infrared thermography camera is widely used in material characteristic assessment, boiler heat distribution analysis, process control, and building insulation assessments that indicate system deficiencies. This technique has also recently been used in human-body-related temperature measurements with potential for application to medical fields that include breast cancer examinations, joint muscle disorders, and body reactions under specific conditions. The most significant advantage of infrared thermography cameras to evaluate heat conductivity according to wearing conditions are its inexpensive price, ease-of-use and visual representation of surface heat dispersion on clothing that maintains body temperature and helps dissipate sweat(B. Lee, Hong, & Y. Lee, 2010; Lee, K. Hong, & S. A. Hong, 2007). This technique is also used in a quantitative analysis of thermal sensation when wearing clothes (Choi & Lee, 2008). This study helps develop a method to evaluate the warm feeling of fabrics using an infrared thermal image of a small test specimen. An infrared thermal image helped develop5 types of fabrics for heat storage fabric; consequently, the average temperature difference of the human palm when the fabric is on or off was used for the scale of the fabrics’ warm feeling. The relationshipbetween this average temperature difference on the palm surface Qmax, and warmth keep-ability rate was examined. Fabric had a significant average temperature difference in the infrared thermal image with alow Qmax value and was evaluated with high values in the warmth keep-ability rate. Infrared thermography camera was shown to be effective in the fabric's warm feeling evaluation.

In recently, the method estimated construction's defeat using the infrared thermography was prefer to method of new repair and estimate as a good point that simple of application and save labor, what is more economic than other techniques and can reduce need time. The purpose of this study is to develope the technique to measure the corrosion of reinforcing bars using the infrared thermal photography graphic data. In this page, the former final purpose establishment that galvanic corrosion method of reinforced bars and infrared thermography system, and studied trend of thermography and photography graphic data by parameters of corrosion of specimens, atmosphere temperature, concrete cover depth etc.

This study aims to investigate the qualitative and quantitative performance of concrete defect using Pulsed Thermography (PT) and Pulse Phase Thermography (PPT) techniques. The experimental study was carried out on a concrete specimen in-placed artificial defects with various depths and sizes. The signal-to-noise technique was used to compare the contrast between the two methods. The results showed that the thermal images obtained from PPT show clearer than those from PT (using contrast-based method).

In this study, an experimental test is conducted on a concrete specimen using passive thermography (IRT) which is an effective and modern non-destructive test (NDT) method in detecting delaminations. The present work evaluates the detectability of delaminations with different sizes during the daytime by the absolute contrast technique. In addition, the most suitable time for delamination inspection of concrete structures is also proposed.

In this study, an experimental study of Impulse Thermography was carried out on a concrete specimen with in-placed artificial defects at different depths and dimensions. Then, all the data were processed by Pulse Phase Thermography technique by performing Fast Fourier Transformation. The results were compared with the absolute contrast method.

Recently, accidents caused by the aging of structures are occurring frequently in the world. As a result, maintenance and accident prevention of structures are required. In this study, for the purpose of addressing these issues to solve these problems, we developed a non - destructive inspection technique using thermal imaging and planned damage detection process. we set up a scenario to detect the invisible excursions, cracks, and internal damage by sensing and analyzing the thermal energy radiated by the stainless steel test piece (STS304) with infrared thermal imaging equipment.

The purpose of this research is to consider the qualitative and quantitative performance of reinforced concrete deteriorations using active infrared thermography (IRT) technique. An experiment of five different cases of environmental conditions was conducted on a concrete slab in laboratory. A comparison of the IRT results between normal and reinforced concrete is also discussed. The results showed that the absolute contrast between defective area and non-defective area increases with the increment of ambient temperature. Besides, the values of absolute contrast above delamination obtained from normal concrete showed high than those under effect of reinforcing steel bar.

This research aim to investigate the qualitative and quantitative performance of concrete deteriorations using Pulse Square Thermography (PST) technique. An experimental test of ten cases was conducted on a concrete slab specimen under different meteorological conditions. The results showed that the absolute contrast between defective area and sound area decreases with the falling of ambient temperature. Besides, the delamination with identical size but placed at a deeper position indicates lower absolute contrast than the shallow delamination.

The Infrared-Thermography Technique is widely used for nondestructive evaluation (NDE) of structures due to its convenience. Particularly, various techniques have been tried to detect imperfections such as surface defects and welding defects of steel structures. This paper is a part of a study to detect defects in weld zone in steel structures using Infrared Thermography techniques. Finally, defects were detected by comparing infrared thermal image and surface temperature data of defected area with healthy area.

The purpose of this paper is to find an limitation to detect the defect of damaged asphalt pavement structures for improved infrared thermography. We use heat source of a natural light to detect the defect efficiently. The heat source was applied to the asphalt specimens containing maximum depth of 3cm internal timber. It was found that the depth of 3cm internal timber could be detected by this method. In addition, we used the improved image processing to make the damage zone displayed clear in the image obtained from the thermographic operation.

Existing nondestructive test methods used to measure reinforcement corrosion is based on qualitative measurement of corrosion, and it has many difficulties of use because many equipment and measurement stages are required for application at actual sites. Accordingly, this study was conducted to estimate reinforcement corrosion of concrete structures using infrared thermography method as a method of measuring reinforcement corrosion in concrete. As for the specimen was to measure reinforcement corrosion, D13 reinforcement with size of 200×150×180mm was buried at length of 250mm for covering depth of 20mm and 40mm. Accelerated reinforcement corrosion test was carried out after placement of concrete. As a result of measuring reinforcement corrosion using infrared thermography method, temperature difference of 1~3°C was shown depending on the corrosion stage. There was a correlation in which temperature decreased according to chloride content. Infrared thermography method was confirmed as a useful method for measurement of reinforcement corrosion inside concrete.