High spatial resolution and dynamic OFDR-based method for detecting ship structural response

Ships, as thin-walled structures, experience various structural responses at critical components and may even fail under sustained time-varying wave forces. Understanding the structural behaviors of key components during operation is essential for accurate ship safety assessments. The lack of an effective strain monitoring system that integrates both high spatial resolution and dynamic monitoring capabilities affects the timely detection of these structural responses. This paper presents a high spatial resolution dynamic strain monitoring system using optical frequency domain reflectometry, achieving a system spatial resolution of 0.11 mm, a sensing spatial resolution of 20 mm, and a sampling frequency of 10 Hz. A box girder model of a river-sea-going ship is employed to simulate structural responses under wave-induced conditions. Simulation results validate the system's accuracy. By analyzing strain distribution and variation, this study explores the dynamic collapse behavior of structures under wave forces.