Structural Health Monitoring of aerospace thin plate and shell structures using the inverse finite element method (iFEM)
Ihtisham Khalid, Zahid Ahmed Qureshi, Selda Oterkus, Erkan Oterkus
Abstract
Thin plate and shell structures are widely used in aerospace due to their lightweight nature and efficient load-bearing capabilities, making them attractive for aircraft and spacecraft designs. This study proposes an efficient quadrilateral inverse shell element for thin structures, developed using discrete Kirchhoff assumptions, for Structural Health Monitoring (SHM) applications within the inverse finite element method (iFEM) framework. The proposed inverse formulation is straightforward, computationally efficient, and requires fewer strain sensors for full-field reconstruction than existing inverse elements based on First-Order Shear Deformation Theory (FSDT). These attributes are essential for implementing efficient SHM strategies while lowering overall project costs. The proposed inverse element is rigorously validated using benchmark problems for in-plane, out-of-plane, and general loading conditions. Its performance is compared to that of an existing competitive quadrilateral inverse shell element based on FSDT. For aerospace SHM applications, the inverse element is assessed for its shape-sensing capabilities, material discontinuity and degradation defects characterization, and structural health assessment. This research highlights the ability of the proposed inverse element to enhance SHM applications in aerospace structures, contributing to the development of more reliable and cost-effective monitoring solutions. • Reliable, cost-effective SHM solution for aerospace thin structures. • Quadrilateral inverse shell formulation based on discrete Kirchhoff theory. • Computational advantages with reduced sensor requirements. • Rigorous validation and comparison with competitive inverse shell elements. • Evaluation of shape sensing, defect characterization, and health assessment.