Shape Sensing of Post-Buckling Shear Panels Using Distributed Optical Fiber Sensors and Ko’s Displacement Theory: Comparison with Digital Image Correlation

This paper presents a comparison of out-of-plane displacement measurement techniques for shear-loaded panels, using both a digital image correlation system and a distributed optical fiber sensor system. The digital image correlation system directly determines displacement and strain, while the distributed optical fiber sensor uses Ko’s displacement theory to compute displacement based on measured strain. A Wagner beam test rig is used to perform experimental investigations. The digital image correlation system determines the out-of-plane displacement of the panels, although it is currently suitable only for laboratory applications. Conversely, the distributed optical fiber sensor system offers the significant advantage of being embedded within structures, with potential for future continuous in-flight structural health monitoring. The displacement estimation by the distributed optical system is in agreement with the digital image correlation measurement, excluding the boundary area of the panels, where an extension of Ko’s displacement theory for this specific testing case is required.