An improved inverse finite element method for shape sensing using isogeometric analysis

The inverse finite element method (iFEM) is advisable as accurate and efficient method for structure health monitoring (SHM). The previous standard iFEM uses 0th-order and 1st-order shape functions to reconstruct displacement fields under concentrated load and distributed load, respectively. However, in engineering environmental loads, it is difficult to determine which external load is mentioned above. To solve this problem, this paper proposes an improved iFEM based on isogeometric analysis (IGA), which can achieve a unified description of the displacement fields under the effect of concentrated load, distributed load, or concentrated-distributed-hybrid load. Initially, B-spline functions of order two are employed to reconstruct the strain fields. Then, the shape function order of translations and rotations are deduced based on the section strain theory. Next, these deduced displacement shape functions are further used to reconstruct the deformation field using strain measurement. Finally, a wing structure is subjected to concentrated and distributed loads in simulation analysis and experimental tests. The result shows that improved iFEM is more accurate and effective than standard iFEM in displacement reconstruction.

Automated summary

The study proposed an improved iFEM based on isogeometric analysis to handle different types of external loads, achieving a unified description of displacement fields, and demonstrated through experiments to be more accurate and effective.