Deformation Monitoring of the Underwater Pressure Vessels Using Fiber Bragg Grating Sensor

The present study designed a fiber Bragg grating (FBG) sensor system and numerical analysis model of a cylindrical pressure structure with an I-shaped outer frame to examine the strain variations of pressure structures at various diving depths. The results were then compared and verified with those two methods. Experimental results show that when equal pressure was imposed on the cylindrical structure, the maximum strain (50 m depth) at 0°, 90°, and 180° were 130.39 μe, 67.84 μe, and 60.2 μe, respectively. The strain results at the position (90° and 180°) were similar to those obtained in the numerical analysis. This study established an accurate and practical assessment technique to monitoring the strain of underwater pressure vessels.