Localization and identification of structural nonlinearities using cascaded optimization and neural networks

Date

2017-10-01

Author

Koyuncu, A.
Ciğeroğlu, Ender
Özgüven, Hasan Nevzat

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In this study, a new approach is proposed for identification of structural nonlinearities by employing cascaded optimization and neural networks. Linear finite element model of the system and frequency response functions measured at arbitrary locations of the system are used in this approach. Using the finite element model, a training data set is created, which appropriately spans the possible nonlinear configurations space of the system. A classification neural network trained on these data sets then localizes and determines the types of all nonlinearities associated with the nonlinear degrees of freedom in the system. A new training data set spanning the parametric space associated with the determined nonlinearities is created to facilitate parametric identification. Utilizing this data set, initially, a feed forward regression neural network is trained, which parametrically identifies the classified nonlinearities. Then, the results obtained are further improved by carrying out an optimization which uses network identified values as starting points. Unlike identification methods available in literature, the proposed approach does not require data collection from the degrees of freedoms where nonlinear elements are attached, and furthermore, it is sufficiently accurate even in the presence of measurement noise. The application of the proposed approach is demonstrated on an example system with nonlinear elements and on a real life experimental setup with a local nonlinearity.

Subject Keywords

Control and Systems Engineering, Signal Processing, Mechanical Engineering, Civil and Structural Engineering, Aerospace Engineering, Computer Science Applications

URI

https://hdl.handle.net/11511/35404

Journal

MECHANICAL SYSTEMS AND SIGNAL PROCESSING

DOI

https://doi.org/10.1016/j.ymssp.2017.03.030

Collections

Department of Mechanical Engineering, Article

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Citation Formats

A. Koyuncu, E. Ciğeroğlu, and H. N. Özgüven, “Localization and identification of structural nonlinearities using cascaded optimization and neural networks,” MECHANICAL SYSTEMS AND SIGNAL PROCESSING, pp. 219–238, 2017, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/35404.