Detection of Weld Imperfection Based on Vibration-Based Method

Kong, Kein Fei (2020) Detection of Weld Imperfection Based on Vibration-Based Method. Final Year Project (Bachelor), Tunku Abdul Rahman University College.

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Abstract

Welding joint is a very common type of joining methods that widely used in industrial application. For critical structural system that consists of weld joints such as aerospace appliance, building structure and bridge, the damage and imperfection occurs will causing the structural failure and catastrophic incidents. Hence, early detection of imperfection occur in weld joints is an essential procedure to prevent further problems. However, weld joints may consist of invisible small imperfection which requires time consuming and complicated procedure of nondestructive inspection methods to localize them. Therefore, a method to detect these invisible imperfections in the time effective and accurate manner is necessary. It is known that the existence of any imperfection or damage in the structure will alter the structural vibration modes. This project proposed a methodology based on the structural frequency response changes to detect weld imperfection. In this project, two damage cases with different severity have been considered for impact testing to obtain the frequency responses. The response obtained has been analyzed to identify the damage location and quantify the severity of damage. As result, the location and severity of both internal and external crack occurred in weld structure has been classified by using the information of frequency response. It has shown that the vibration-based damage detection method is able to detect, locate and assess the extent of imperfection occurred in weld structure.