An accurate shape sensing methodology for laminated composite wing spars based on the nonlinear deformation theory

Official URL: https://dx.doi.org/10.1016/j.ast.2025.110444

Real-time monitoring of nonlinear deformation in laminated composite tubular beams presents a critical challenge, particularly in high-aspect-ratio wing spar applications, where the existing shape sensing techniques often fail to achieve adequate accuracy. To solve this problem, this paper introduces a novel nonlinear shape sensing methodology for laminated composite tubular beams leveraging discrete strain measurements. The approach is rooted in von Karman nonlinear deformation theory and the nonlinear strain field formulations and governing differential equations are derived for employing in inverse finite element method (iFEM). The calculation method of transformed elastic constants is presented based, and the constitutive equations guide the determination of section strain orders and displacement functions. Discrete strain measurements are then employed to estimate section strain functions accurately. A deformation monitoring model on iFEM method is established and solved iteratively using the Newton-Raphson algorithm. Validation tests is performed on a laminated composite beams representing aerospace structures. Numerical and experimental results highlight a 30 % improvement in displacement prediction compared to the traditional iFEM method, which demonstrated the robustness and precision of the proposed approach. Hence, the proposed iFEM methodology offers a reliable and efficient tool for shape sensing and structural health monitoring as well as safety assurance in marine, offshore and aerospace industries.