This paper presents a novel bolt-loosening detection technique using image information of bolted connections in the steel bridge. The technique consists of 5 steps: (1) taking a picture for a bolted joint, (2) converting to binary image, (3) extracting individual nuts, (4) extracting outlines of the nuts, and (5) identifying rotation angles of the nuts and detecting bolt-loosening. The applicability of the proposed technique is evaluated by experimental tests with several bolt-loosening scenarios.

• 박재형(부경대학교 해양공학과 BK21+ 계약교수, 공학박사) | Park, Jae-Hyung
• 김태환(부경대학교 해양공학과, 석사과정) | Kim, Tae-Hwan
• 김정태(부경대학교 해양공학과 교수, 공학박사) | Kim, Jeong-Tae 교신저자