Browsing by Author "Dessena, Gabriele"
Now showing 1 - 11 of 11
Results Per Page
Sort Options
Item Open Access A tutorial on the Loewner-based system identification and structural health monitoring approach for mechanical systems.(Cranfield University, 2023-04-19 09:14) Dessena, GabrieleThe tutorial should be considered complementary material for the article "A Loewner-based system identification and structural health monitoring approach for mechanical systems" (DOI: 10.1155/2023/1891062). The tutorial illustrates, via a simple example, the capability of the Loewner Framework for System Identification and Structural Health Monitoring. The second goal of this tutorial is to make available a Loewner Framework program for MATLAB to the public based on the published work. Please cite [1-5] when using this software for your work or research, Thank you. This tutorial is linked to the following article: G. Dessena, M. Civera, L. Zanotti Fragonara, D. I. Ignatyev, J. F. Whidborne, A Loewner-based system identification and structural health monitoring approach for mechanical systems, Structural Control and Health Monitoring, Vol. 2023 (2023). (DOI: 10.1155/2023/1891062) The repository entry contains five files: 1. data_9dof.mat: the data for the tutorial model; 2. LF_id.m: the script for the LF-based System Identification; 3. loewner.m: the Loewner Matrix function; 4. LF_tutorial.mlx: the LF tutorial in MATLAB live mode 5. LF_tutorial.pdf: the LF tutorial in pdf. The program was created in MATLAB 2020a, compatibility with earlier or later versions is not guaranteed. References [1] G. Dessena, M. Civera, L. Zanotti Fragonara, D. I. Ignatyev, J. F. Whidborne, A Loewner-based system identification and structural health monitoring approach for mechanical systems, Structural Control and Health Monitoring, Vol. 2023 (2023). (DOI: 10.1155/2023/1891062) [2] G. Dessena, A Loewner-based system identification and structural health monitoring approach for mechanical systems, CORD repository (2021) (DOI: 10.17862/cranfield.rd.16636279) [3] A. J. Mayo, A. C. Antoulas, A framework for the solution of the generalized realization problem, Linear Algebra and its Applications 425, pp. 634–662 (2007). (DOI:10.1016/j.laa.2007.03.008) [4] S. Lefteriu, A. C. Antoulas, A New Approach to Modeling Multiport Systems From Frequency-Domain Data, IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems, Vol. 29, No. 1, pp. 14–27 (2010). (DOI: 10.1109/TCAD.2009.2034500) [5] S. Lefteriu, A. C. Ionita, A. C. Antoulas, Modeling Systems Based on Noisy Frequency and Time Domain Measurements, Lecture Notes in Control and Information Sciences, vol. 398/2010, 365-368 (2010). (DOI: 10.1007/978-3-540-93918-4_33)Item Open Access Data supporting: 'Ground Vibration Testing of a Flexible Wing: A Benchmark and Case Study'(Cranfield University, 2023-05-04 16:22) Dessena, GabrieleThis CORD entry contains the experimental data underlying the journal article Ground Vibration Testing of a Flexible Wing: A Benchmark and Case Study published in Aerospace by MDPI. The document XB-2_Dataset.pdf serves as the explanatory note for the data contained in data_xb2.matItem Open Access A global-local meta-modelling technique for model updating(Elsevier, 2023-10-09) Dessena, Gabriele; Ignatyev, Dmitry I.; Whidborne, James F.; Zanotti Fragonara, LucaThe finite element model updating procedure of large or complex structures is challenging for engineering practitioners and researchers. Iterative methods, such as genetic algorithms and response surface models, have a high computational burden for these problems. This work introduces an enhanced version of the well-known Efficient Global Optimisation technique to address this issue. The enhanced method, refined Efficient Global Optimisation or rEGO, exploits a two-step refinement and selection technique to expand the global search capability of the original method to a global–local, or hybrid, search capability. rEGO is tested and validated on four optimisation test functions against the original methods and genetic algorithms with different settings. Good results in terms of precision and computational performance are achieved, so an application for model updating is sought. A penalty function for the finite element model updating is identified in residuals of the modified total modal assurance criterion. Finally, rEGO for finite element model updating is implemented on a hybrid, numerical and experimental, case study based on a well-known experimental dataset and on a higher dimension finite element model of a wing spar. Satisfactory results in terms of precision and computational performance are achieved when compared to the original methods and genetic algorithms, needing two orders of magnitude fewer evaluations and achieving comparable results in terms of precision.Item Open Access Ground vibration testing of a flexible wing: a benchmark and case study(MDPI, 2022-08-10) Dessena, Gabriele; Ignatyev, Dmitry I.; Whidborne, James F.; Pontillo, Alessandro; Zanotti Fragonara, LucaBeam-like flexible structures are of interest in many fields of engineering, particularly aeronautics, where wings are frequently modelled and represented as such. Experimental modal analysis is commonly used to characterise the wing’s dynamical response. However, unlike other flexible structure applications, no benchmark problems involving high-aspect-ratio flexible wings have appeared in the open literature. To address this, this paper reports on ground vibration testing results for a flexible wing and its sub-assembly and parts. The experimental data can be used as a benchmark and are available to the aeronautical and structural dynamics community. Furthermore, non-linearities in the structure, where present, were detected. Tests were performed on the whole wing as well as parts and sub-assembly, providing four specimens. These were excited with random vibration at three different amplitudes from a shaker table. The modal properties of a very flexible high-aspect-ratio wing model, its sub-assembly and parts, were extracted, non-linear behaviour was detected and the experimental data are shared in an open repository.Item Open Access Ground Vibration Testing of a High Aspect Ratio Wing with Revolving Clamp(Cranfield University, 2022-12-01 09:17) Dessena, Gabriele; Ignatev, Dmitrii; Whidborne, James; Pontillo, Alessandro; Zanotti Fragonara, Luca33rd Congress of the International Council of the Aeronautical Sciences (ICAS). Abstract: The advancements in the aeronautical industry and research on materials and manufacturing methods in the last 70 years have been shifting the paradigm of wing design to high aspect ratio flexible wings. These wings can show a varying behaviour in different operating conditions, as per the nature of their geometry and materials. This work proposes a case study of a high aspect ratio flexible wing in order to study the effect of operating conditions on its structural properties. To test different operating conditions on the ground, a revolving clamp is designed to attach the specimen to a clamp-on shaker. A clear relationship between the wing’s modal properties, and so structural properties, and the angle the clamp sets is found.Item Open Access Ground vibration testing of a high aspect ratio wing with revolving clamp(ICAS, 2022-11-28) Dessena, Gabriele; Ignatyev, Dmitry I.; Whidborne, James F.; Pontillo, Alessandro; Zanotti Fragonara, LucaThe advancements in the aeronautical industry and research on materials and manufacturing methods in the last 70 years have been shifting the paradigm of wing design to high aspect ratio flexible wings. These wings can show a varying behaviour in different operating conditions, as per the nature of their geometry and materials. This work proposes a case study of a high aspect ratio flexible wing in order to study the effect of operating conditions on its structural properties. To test different operating conditions on the ground, a revolving clamp is designed to attach the specimen to a clamp-on shaker. A clear relationship between the wing’s modal properties, and so structural properties, and the angle the clamp sets is found.Item Open Access Identification of flexible structures dynamics.(Cranfield University, 2023-04) Dessena, Gabriele; Ignatyev, Dmitry I.; Whidborne, James F.; Zanotti Fragonara, LucaThe pursuit of aerodynamic efficiency and the advances in materials technology, particularly in composite material, has contributed to shifting the paradigm of wing design to high aspect ratio wings. Increasing the span, for decreasing drag, and using composite lightweight materials make the new wing very flexible and prone to nonlinear dynamic behaviour. With nonlinearities, increasing challenges arise for the identification and modelling of the wing. These challenges cannot be overlooked for flexible structures as these models are critical for the prediction of aeroelastic phenomena. Hence, it is fundamental to expand the knowledge of the behaviour of these structures through the identification and modelling of sample flexible wing models. In this work, a series of methods and approaches are proposed and employed for the identification and modelling of a flexible wing. First, a system identification technique in the frequency domain, the Loewner Framework, is applied for modal parameters extraction in mechanical systems for structural health monitoring. This new technique, with a linear reduced order model, is used to characterise the flutter behaviour of a flexible wing. The results are compared to similar techniques. A thorough experimental campaign is run on a flexible wing model to characterise its nonlinear behaviour and the underlying linear system. In particular, nonlinearities are detected, identified and quantified. Then, a meta-model technique based on Kriging, the refined Efficient Global Optimisation, is proposed for finite element model updating. First, the technique is used for damage detection in benchmark structures, then, it is employed for the validation of component-based strategies for model updating of a flexible wing.Item Open Access A Kriging approach to model updating for damage detection(Springer, 2022-06-16) Dessena, Gabriele; Ignatyev, Dmitry I.; Whidborne, James F.; Zanotti Fragonara, LucaFor complex or large structures, the model updating process can be long and tedious and numerical methods can be computationally expensive. Hence, practitioners and researchers often resort to meta-modelling techniques when large problems are met. Even so, traditional methodologies, such as the Efficient Global Optimisation, can be slow and give sub-optimal results. This work proposes a new methodology for the model updating of numerical systems based on a novel Kriging approach for the scope of damage detection and quantification. The framework proposed is based on a global-local optimisation strategy recently developed by the authors, the refined Efficient Global Optimisation, herein used to tweak finite element models’ parameters to match the modal data extracted from a numerical system by using the residuals of the modified total modal assurance criterion. The main advantage to existing direct optimisation and meta-modelling frameworks is the more efficient use of computational e ort for higher dimensional problems, which is verified with the use of a numerical system.Item Open Access A Loewner-based system identification and structural health monitoring approach for mechanical systems(Wiley, 2023-04-18) Dessena, Gabriele; Civera, Marco; Zanotti Fragonara, Luca; Ignatyev, Dmitry; Whidborne, James F.Data-driven structural health monitoring (SHM) requires precise estimates of the target system behaviour. In this sense, SHM by means of modal parameters is strictly linked to system identifcation (SI). However, existing frequency-domain SI techniques have several theoretical and practical drawbacks. Tis paper proposes using an input-output system identifcation technique based on rational interpolation, known as the Loewner framework (LF), to estimate the modal properties of mechanical systems. Pioneeringly, the Loewner framework mode shapes and natural frequencies estimated by LF are then applied as damage-sensitive features for damage detection. To assess its capability, the Loewner framework is validated on both numerical and experimental datasets and compared to established system identification techniques. Promising results are achieved in terms of accuracy and reliability.Item Open Access Presentation: A Kriging Approach to Model Updating for Damage Detection(Cranfield University, 2022-07-04 01:10) Dessena, GabrieleThis are the presentation slides for the presentation delivered on the 4.7.2022 at the 10th European Workshop on Structural Health Monitoring in Palermo, Italy. The presentation refers to the "A Kriging Approach to Model Updating for Damage Detection" paper that can be found at https://doi.org/10.1007/978-3-031-07258-1_26Item Open Access Presentation: Ground Vibration Testing of a High Aspect Ratio Wing with Revolving Clamp(Cranfield University, 2022-09-06 09:19) Dessena, GabrieleThis is the presentation delivered on the 8.9.2022 at the 33rd Congress of the International Council of the Aeronautical Sciences (ICAS) in Stockholm, Sweden. The presentation refers to the "Ground Vibration Testing of a High Aspect Ratio Wing with Revolving Clamp" paper that can be found at https://doi.org/10.17862/cranfield.rd.20486229