Structural health monitoring of cylindrical bodies under impulsive hydrodynamic loading by distributed FBG strain measurements

In this work, we leverage a modal decomposition analysis to develop a methodology for the live structural health monitoring. The proposed methodology relies on punctual strain measurements performed utilizing a fiber bragg grating (FBG) system. We propose an experimental measurement chain for the live monitoring of the structural kinetics and the distributed stress field. Its effectiveness is verified by performing experiments on the water entry of compliant bodies. Structural punctual strains are synchronously acquired at several locations by FBG sensors through a homemade high-speed optical interrogator. The structural deformation is reconstructed through its decomposition over a finite number of mode shapes. The combination of the high-speed FBG interrogator with the computationally inexpensive reconstruction technique based on modal decomposition allows for real time monitoring of structures subjected to impulsive loadings.