Membrane Shape and Load Reconstruction from Measurements Using Inverse Finite Element Analysis

Alioli, Mattia; Masarati, Pierangelo; Morandini, Marco; Carpenter, Trenton; Osterberg, N. Brent; Albertani, Roberto

doi:10.2514/1.j055123

Cited by 11 publications

(4 citation statements)

References 34 publications

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“…It is suitable for reconstructing a typical beam structure instead of objects with a complex structure. Alioli et al [168] reconstructed the deformation feld and pressure feld of the membrane wing through the construction of the membrane element with the inverse fnite element method and proved that the method has good real-time performance. Te inverse fnite element method does not need to analyse the material properties and the object modes in advance.…”

Section: High-precision Shape Reconstruction Of Antenna Arraymentioning

confidence: 99%

Structural-Electromagnetic-Thermal Coupling Technology for Active Phased Array Antenna

Wang

et al. 2023

International Journal of Antennas and Propagation

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Active phased array antenna (APAA) is a representative of complex electronic equipment, and it plays significant roles in scenarios such as battlefield situation perception, aviation guidance, and communication. It has become the core equipment in land, navigation, and aeronautical applications. With the continuous improvement of technical changes and military requirements, the working frequency band, pointing accuracy, gain, and low sidelobe level of APAA increase, and the multi-disciplinary design contradiction between antenna electrical performance and structure and temperature becomes increasingly prominent. As a result, the electrical performance of APAA in service is prone to be affected by the external complex environments. The structural-electromagnetic-thermal (SET) coupling problem has become a key problem restricting the development of APAA. This paper has summarized the structural features and environmental loads of advanced APAA on different platforms and provided design basis and principle for antenna designer. And then the SET coupling theory of APAA has been introduced, which can be applied in both the design and manufacturing stage, as well as the performance control technology in service environment of APAA. This theory helps to analyze the impact of environmental factors, such as antenna structure deformation, radome high-temperature ablation, and feed errors, on the antenna's performance. For 128 × 768 spaceborne array antenna, in the range of 25∼85°C, the gain of antenna decreases with the increase of operating temperature and decreases by 0.015 dB with each increase of 1°C. The key design parameters in the fields of antenna manufacturing accuracy, efficient heat dissipation, and lightweight design are also analysed; for 32 × 32 rectangular planar phased array antenna, the gain of antenna decreases by 2.715 dB when the random error of installation position in x, y, and z direction reaches 1/10 of the wavelength. In addition, condition monitoring, displacement field reconstruction, and electrical performance compensation of APAA have also been touched to help engineers maintain and guarantee the antenna performance throughout its life cycle. Finally, the future research direction of SET technology of APAA has been discussed, and SET technology is extended to more fields such as antenna parameter uncertainty, high-frequency circuit electronics manufacturing, and electronic equipment performance guarantee.

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Section: High-precision Shape Reconstruction Of Antenna Arraymentioning

confidence: 99%

Structural-Electromagnetic-Thermal Coupling Technology for Active Phased Array Antenna

Wang

et al. 2023

International Journal of Antennas and Propagation

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“…In Equation ( 16), the continuous experimental section strains, E and K, are used for the notational brevity only. In fact, they are not necessarily need to be available in the iFEM analysis, since one can directly use the available discrete data, E i and K i , when performing the area-integrals in Equation (16). This part will be detailed in the remainder of this section.…”

Section: The Weighted-least-squares Functional and Its Discretization Using Nurbs Basis Functionsmentioning

confidence: 99%

“…Up until now, three different inverse-plate/shell elements are developed based on Lagrangian shape functions, namely iMIN3 [ 13 ], iQS4 [ 14 ], and iCS8 [ 15 ] elements. Moreover, nonlinear membrane shape and transverse load reconstruction were performed by employing classical shell theory in the iFEM formulation [ 16 ]. Besides, various damage detection strategies [ 17 , 18 ] were examined for various engineering structures utilizing the iQS4 element.…”

Section: Introductionmentioning

confidence: 99%

Isogeometric iFEM Analysis of Thin Shell Structures

Kefal

Öterkuş

2020

Sensors

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Shape sensing is one of most crucial components of typical structural health monitoring systems and has become a promising technology for future large-scale engineering structures to achieve significant improvement in their safety, reliability, and affordability. The inverse finite element method (iFEM) is an innovative shape-sensing technique that was introduced to perform three-dimensional displacement reconstruction of structures using in situ surface strain measurements. Moreover, isogeometric analysis (IGA) presents smooth function spaces such as non-uniform rational basis splines (NURBS), to numerically solve a number of engineering problems, and recently received a great deal of attention from both academy and industry. In this study, we propose a novel “isogeometric iFEM approach” for the shape sensing of thin and curved shell structures, through coupling the NURBS-based IGA together with the iFEM methodology. The main aim is to represent exact computational geometry, simplify mesh refinement, use smooth basis/shape functions, and allocate a lower number of strain sensors for shape sensing. For numerical implementation, a rotation-free isogeometric inverse-shell element (isogeometric Kirchhoff–Love inverse-shell element (iKLS)) is developed by utilizing the kinematics of the Kirchhoff–Love shell theory in convected curvilinear coordinates. Therefore, the isogeometric iFEM methodology presented herein minimizes a weighted-least-squares functional that uses membrane and bending section strains, consistent with the classical shell theory. Various validation and demonstration cases are presented, including Scordelis–Lo roof, pinched hemisphere, and partly clamped hyperbolic paraboloid. Finally, the effect of sensor locations, number of sensors, and the discretization of the geometry on solution accuracy is examined and the high accuracy and practical aspects of isogeometric iFEM analysis for linear/nonlinear shape sensing of curved shells are clearly demonstrated.

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“…Moreover, with notable exceptions (Ref. 19), the approaches in the literature are inherently linear, whereas in finite strain theory the general relationship between strain and displacement is nonlinear. The modal shape functions may be conveniently evaluated for helicopter rotor blades through an equivalent 1D beam model.…”

Section: Introductionmentioning

confidence: 99%