Structural Testing of Navy Vessels Using Bragg Gratings and a Prototype Digital Spatial Wavelength Domain Multiplexing (DSWDM) System

Abstract

Repairing and maintaining the Fleet have been long‐standing problems for the Navy. In recent years, decreasing resources and Fleet assets have made repair and maintenance an even more difficult problem. In response to these pressures, Navy personnel have been seeking new methods to reduce overall maintenance costs. One such approach has been to instrument ships during operation with resistance strain gage technology in order to provide information for estimating the structural health of ship hulls. To date, a limited number of naval ships have been instrumented in this way, and have collected data to validate computer models that predict damage accumulation over the expected service life of the vessel (Adamchak 1984; Sikora 1983). The Navy is currently developing a new ship structural health monitoring system based on fiber optic technology. Application of this new health monitoring system to U.S. Navy vessels will improve maintenance programs by predicting need‐based maintenance schedules, thereby eliminating costly cyclic preventative maintenance schedules. This new system will also increase operational availability and ship survivability by providing ship operators real‐time information concerning the state of the ship structure. This paper describes the operational capabilities of this new system and recent test results on large‐scale naval structures including a U.S. Navy Landing Platform Dock 17 (LPD 17) ship propeller.

Study on optical 3D angular deformations measurement

“…The measurement for 3D angular deformations is one of most difficult and significant issues in navy and shipbuilding industry around the world. Although many measurement methods have been proposed in recent years, such as inertia matching method [1,2] , fiber Bragg gratings method [3,4] and photogrammetry [5,6] , an effective and mature measurement for 3D ship angular deformations is still unavailable.…”

Determination of the static pressure loads on a marine composite panel from strain measurements utilising artificial neural networks

“…These systems provide real-time information concerning the state of the ship structure, can be employed to validate computer models, increase operational attainability and ship service life and can lead to reductions in the ongoing maintenance costs. [4][5][6] Computational fluid dynamics (CFD) techniques provide a method to solve these problems; however, it is generally accepted that CFD codes have difficulties in estimating the impact loads. 7 CFD methods are time consuming, making statistical estimations of the response variables in the sea difficult.…”