Shape Sensing with Sparse Strain Information for Aerospace Applications

Abstract

The reconstruction of the deformations from strain measurements is usually called shape sensing and is of interest in the field of structural health monitoring. In this paper the problem is studied with a limited amount of strain data since for real applications and an on-line monitoring it might be unfeasible to employ a large amount of sensors. In this context the deformations are computed with the inverse Finite Element Method (iFEM) taking advantage from a preliminary strain pre-extrapolation done with the Smoothing Element Analysis (SEA). The results are then compared with another common shape sensing method, the so-called Modal Method (MM), using as study case a composite wing-like structure. Noise and uncertainties and their influences on the results are also assessed. The outcome obtained points out that iFEM is largely improved after the preliminary strain pre-extrapolation. However, for this study case, the Modal Method performs better despite the intrinsic disadvantage in requiring the material properties of the structure (compared to iFEM, where no constitutive relation is needed), which affects the results in case uncertainties are present in the system.