3D Optic Sensor

The project involves the development of an algorithm for a fiber-optic inclinometer measurement system (FOS) consisting of a cylindrical glass-fiber rod in which fiber-optic Fiber Bragg Gratings (FBGs) are integrated along the longitudinal axis. Based on the FOS measurement data recorded along the rod, the spatial deformation state variables are to be determined for both small and large three-dimensional deformations. In addition, local material stresses are to be derived and compared with defined limit states in order to verify ultimate limit states, serviceability limit states, and fatigue or durability limit states of structural components. For this purpose, an evaluation algorithm is developed within the project that converts the FOS measurement quantities into inclinometer, extensometer, and local strain information. This conversion is achieved by coupling the measurement data with a specially developed inverse finite element program and an optimization algorithm. The project builds on an algorithm that has already been successfully developed for an FOS lamella measurement system with a rectangular cross-section, in which two embedded fiber-optic sensors were combined into a single measurement system. The objective of the project is to further develop this proven lamella measurement system with a rectangular cross-section and two embedded fiber-optic sensors into an FOS measurement system with a circular cross-section and three embedded fiber-optic sensors. This new system is particularly suitable for measuring large deflections and complex three-dimensional deformations.