Optimisation of inverse Finite Element Method for shape sensing of thin-walled cylinders by using Generalised Beam Theory

Abstract

The inverse Finite Element Method (iFEM) can reconstruct the deformation of structures based on measured strains. This procedure has important applications in Structural Health Monitoring. However, its accuracy depends on the number of the in-situ strain gauges and for shell structures with complex deformation, this number can easily become too high for practical use. Generalised Beam Theory (GBT) can describe the complex deformation of any thin-walled beam member as a linear combination of pre-determined cross-section deformation modes. Instead of shell finite elements, GBT uses bar finite elements. Using these advantages, this paper proposes an iFEM/GBT formulation for the shape sensing of thin-walled cylinders. Great reduction of strain gauges is in this way achieved in comparison with the use of the classic inverse-shell finite elements.