Develop Sonic Infrared Imaging Nde For Local Damage Assessment In Civil Structures

DEVELOP SONIC INFRARED IMAGING NDE FOR LOCAL DAMAGE ASSESSMENTIN CIVIL STRUCTURESbyQi HeDecember 2010Advisor: Dr. Xiaoyan HanMajor: Electrical EngineeringDegree: Doctor of PhilosophyNondestructive Evaluation (NDE) is an interdisciplinary field of study, which isconcerned with the development of analysis techniques and measurement technologiesfor the quantitative characterization of materials, tissues and structures. Ultrasonic IRImaging is a novel NDE technique, which combines a short ultrasonic pulse excitationand infrared imaging to detect defects in materials and structures. In this technique, asound pulse with a frequency in the range of 20-40 kHz is infused on a target materialfor a short duration (usually less than one second). The sonic/ultrasonic sound wavestravel into the material and cause rubbing and clapping between the surfaces of anydefects (such as cracks, delamination) that may be present in that material. The rubbingcauses friction that generates heat in the defect area and ultimately raises thetemperature at that region. An infrared video camera is set up to record the series of IRradiation change from the target object. Ultrasonic Infrared Imaging technique hasseveral advantages compared with other traditional NDE techniques. This technique isable to detect both surface and subsurface cracks and it is effective for metallic, ceramicand composite materials, it is also very efficient for detecting delaminations in coupled