Infrared Thermography​-Nondestructive Testing and Evaluation​ in Structural Analysis​

Nondestructive Testing and Evaluation​ in Structural Analysis​
Infrared Thermography​

1. Nondestructive Testing and Evaluation  in Structural Analysis Infrared Thermography Lecturer :   Prof. Dr. Esra Mete Güneyisi  December 2023

2. Introduction Infrared thermography is a technique that involves detecting and converting infrared energy emitted by an object into temperature data, which is then displayed as an image showing the temperature distribution.  All objects with a temperature above absolute zero emit infrared radiation. The amount and type of radiation depend on the object's temperature.

3. Detection of Infrared Radiation Infrared cameras, also called thermal cameras, are the primary tools used in infrared thermography. These cameras have sensors that can detect infrared radiation and convert it into an electronic signal. The electronic signals from the infrared camera are processed to create a thermal image or video. In this image, different colors or shades represent different temperatures. Warmer areas appear as brighter, while cooler areas appear darker.

4. Infrared thermography camera

5. Types of infrared thermography Passive:  It relies on the natural heat emissions of objects or structures. All objects with a temperature above absolute zero emit infrared radiation, and passive thermography captures this radiation without the need for an external heat source. Active:  It involves the application of an external heat source to the object or structure being inspected. The surface temperature response is then captured by an infrared camera, revealing temperature variations and patterns.

6. Uses of  Passive IRT  in Structures Moisture Detection: Passive infrared thermography is effective in detecting moisture within building materials. Moist areas tend to have different thermal properties, causing temperature variations that can be captured by the infrared camera.

7. Uses of  Active IRT  in Structures Concrete and Structural Inspections: Active thermography is used to inspect concrete and other structural materials for defects such as delamination, voids, and cracks. The heat excites the material, and irregularities are detected based on variations in thermal response.

8. The relevance of infrared thermography in civil engineering Infrared thermography allows for non-destructive testing of structures. It helps identify potential issues such as moisture infiltration, insulation deficiencies, and structural defects without the need for physical intervention or damage to the structure.

9. Infrared thermography and  Structural Inspections The application in concrete structures is mainly focused on the detection of surface defects, porosity, cracks, damage assessment and, particularly in the case of reinforced concrete bridges, in the detection of delamination and voids. 

10.            b) Thermogram Detection of delamination: a) Digital photography  

11.                        b) Thermogram Application in bridge infrastructure: a) Digital photography  

12. Advantages and limitations Infrared thermography can be applied over large distances, analyze and inspect large areas in small time intervals, and provide easy results and quick interpretation; besides having a simple instrumentation. In most cases, all it takes to observe thermal images are a thermographic camera, the camera support and a video output. Despite the many advantages offered by this technique in the inspection, the equipment may be expensive and insensitive to detect the depth of defects and anomalies in the concrete. In addition, the testing is highly influenced by environmental conditions, such as wind, solar radiation, humidity and surface emissivity

13. Thank   You  Prepared by : Rouna Hami  220000888090