Three-Dimensional Shape Sensing by Inverse Finite Element Method Based on Distributed Fiber-Optic Sensors

Abstract

Shape sensing, identifying the shape of the structure based on sensor, which was installed on the structure, is an important technology for structural health monitoring (SHM). It contributes monitoring the condition of the structure, feedback control, and fatigue estimation. By installing fiber-optic sensor on the structure like nerves, the deformed shape can be identified based on inverse finite element method (iFEM) from the measurement strain. The measurement error and the placement of fiber-optic sensor affect the result of shape sensing. Here we show the shape sensing of a bended stiffened panel in the simulation and verify the influence of the measurement error and the sensor placement. The deflection of the plate is identified with an error less than 1% of maximum deflection. The mean percent difference (MPD) calculated from the measurement strain giving Gaussian noise with a standard deviation of 5% of the maximum strain was 2.86%. Furthermore, with simple bending deformation, it was found that shape sensing can be performed with less sensor placement. Our results demonstrate that the realistic sensor performance and sensor placement enable shape sensing of local structure of ship structure such as stiffened panel.