A Triangular Inverse Shell Element for Efficient Structural Health Monitoring of Thin-Walled Structures
Thin shell structures hold a prominent place in high-performance engineering, owing to their impressive strength-to-weight ratio and distributed load-bearing capabilities. However, the structural health monitoring (SHM) of such structures faces significant challenges due to the computational intensity and dense sensor requirements of existing solutions. Traditional inverse methods, often grounded in the First Order Shear Deformation Theory (FSDT), are susceptible to shear locking and suffer from slow convergence rates when dealing with thin geometries. This necessitates extensive sensor networks to counterbalance the slow convergence and high computing demands of FSDT-based inverse methodologies.
To tackle these limitations, researchers from the National University of Sciences & Technology in Islamabad and the University of Strathclyde in Glasgow have introduced the iKS3 element. This innovative formulation is detailed in their article published in the International Journal of Mechanical System Dynamics (DOI: 10.1002/msd2.12141). The iKS3 is built on classical plate theory (CPT) assumptions, which effectively eliminate the need for transverse shear strain components and sidestep the numerical complexities linked with shear deformation modeling in thin shells.
The iKS3 stands out from FSDT-based inverse elements by providing enhanced numerical stability and quicker convergence across various complex loading conditions. Validation studies demonstrate that the iKS3 consistently outmatches inverse elements based on the first-order shear Deformation Theory (FSDT). This superior performance is due to the exclusion of shear deformation terms, simplifying the inverse formulation and enhancing both computational efficiency and applicability in practice.
Beyond displacement reconstruction, the iKS3 method adeptly identifies and quantifies structural degradation using a reliable damage index derived from reconstructed strain fields. This dual capability for kinematic reconstruction and defect assessment enhances its relevance for real-time SHM applications, where computational efficiency and diagnostic precision are pivotal.
Prof. Erkan Oterkus, co-author of the study, remarked, “The iKS3 element offers a computationally efficient path forward for monitoring thin-walled structures in real-time. By reducing the number of required sensors without compromising accuracy, it offers a practical solution for industry-scale monitoring systems.”
Led under the guidance of Prof. Erkan Oterkus, this research directly addresses the challenges involved in monitoring thin shell structures. By lessening dependency on dense sensor networks and overcoming the numerical challenges typical of traditional FSDT-based inverse formulations, the iKS3 element emerges as a viable and efficient solution for real-world SHM applications. Its computational strengths and diagnostic capabilities mark a significant advancement toward enabling efficient, scalable, and accurate monitoring of critical infrastructures in aerospace, naval, and energy sectors.
The International Journal of Mechanical System Dynamics (IJMSD) is an open-access journal committed to exploring the crucial impacts of mechanical system dynamics throughout the lifecycle of contemporary industrial equipment. The journal welcomes research and reviews on dynamics associated with advanced theory, modeling, computation, analysis, software, design, control, manufacturing, testing, and evaluation of mechanical systems across various scales integrated with diverse systems such as electronic, electrical, optical, thermal, magnetic, acoustic, aero, and fluidic systems.
In summary, the development of the iKS3 element marks a significant milestone in the structural health monitoring of thin-walled structures. Its ability to efficiently process and diagnose structural conditions with reduced sensor networks embodies a leap forward in SHM technology, promising robust applications across multiple high-stakes industries.
