Laboratory for Dynamics of Machines and Structures 
Multi-Level Curvature-Based Parametrization and Model Updating Using a 3D Full-Field Response
 K. Zaletelj, D. Gorjup, J. Slavič and M. Boltežar
Mechanical Systems and Signal Processing, 2023

download pdf   https://doi.org/10.1016/j.ymssp.2022.109927

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Abstract
Model updating improves the correlation between the response of the real structure and the response of the finite-element (FE) model; however, the selection of the updating parameters (parametrization) is crucial for its success. Using full-field modal shapes, a large number of parameters can be updated, \emph{e.g.}, the Young's moduli of all the finite elements; however, the structural response is not necessarily sensitive to an arbitrary parameter, making the optimization problem ill-conditioned. Additionally, the computation of the full sensitivity matrix is not feasible for relatively large FE models. Not all locations are equally important for model updating; at locations of the highest mechanical loads, more focus is required. In this research, the updating parameters are based on the curvature of the 3D full-field experimental shape, where locations with high curvature are associated with high sensitivity. The assumption is initially researched with the Euler-Bernoulli beam elements and second-order tetrahedrons. The proposed method is investigated on numerical and real experiments, where successful updating was confirmed. With the proposed parametrization and updating approach, a geometrically complex structure is parametrized and the parameters updated without significant user input, generalizing the model-updating procedure.
Authors

Assistant

Klemen Zaletelj, PhD Student

  Ladisk, Faculty of Mechanical Engineering, University of Ljubljana
  klemen.zaletelj@fs.uni-lj.si
  +386 1 4771 228
klemengit    
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Assistant

Domen Gorjup, PhD Student

  Ladisk, Faculty of Mechanical Engineering, University of Ljubljana
  domen.gorjup@fs.uni-lj.si
  +386 1 4771 228
domengorjup    
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Professor

Janko Slavič, PhD

  Ladisk, Faculty of Mechanical Engineering, University of Ljubljana
  janko.slavic@fs.uni-lj.si
  +386 1 4771 226
jankoslavic     jankoslavic    
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Professor

Miha Boltežar, PhD

  Ladisk, Faculty of Mechanical Engineering, University of Ljubljana
  miha.boltezar@fs.uni-lj.si
  +386 1 4771 608
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