scholarly journals Parameter identification methods for visco- and hyperelastic material models

2017 ◽  
Vol 2 (2) ◽  
pp. 147-167 ◽  
Author(s):  
Michael A. Kraus ◽  
Miriam Schuster ◽  
Johannes Kuntsche ◽  
Geralt Siebert ◽  
Jens Schneider
PAMM ◽  
2014 ◽  
Vol 14 (1) ◽  
pp. 341-342 ◽  
Author(s):  
Nils Hendrik Kröger ◽  
Daniel Juhre

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3429 ◽  
Author(s):  
Chu ◽  
Yuan ◽  
Hu ◽  
Pan ◽  
Pan

With increasing size and flexibility of modern grid-connected wind turbines, advanced control algorithms are urgently needed, especially for multi-degree-of-freedom control of blade pitches and sizable rotor. However, complex dynamics of wind turbines are difficult to be modeled in a simplified state-space form for advanced control design considering stability. In this paper, grey-box parameter identification of critical mechanical models is systematically studied without excitation experiment, and applicabilities of different methods are compared from views of control design. Firstly, through mechanism analysis, the Hammerstein structure is adopted for mechanical-side modeling of wind turbines. Under closed-loop control across the whole wind speed range, structural identifiability of the drive-train model is analyzed in qualitation. Then, mutual information calculation among identified variables is used to quantitatively reveal the relationship between identification accuracy and variables’ relevance. Then, the methods such as subspace identification, recursive least square identification and optimal identification are compared for a two-mass model and tower model. At last, through the high-fidelity simulation demo of a 2 MW wind turbine in the GH Bladed software, multivariable datasets are produced for studying. The results show that the Hammerstein structure is effective for simplify the modeling process where closed-loop identification of a two-mass model without excitation experiment is feasible. Meanwhile, it is found that variables’ relevance has obvious influence on identification accuracy where mutual information is a good indicator. Higher mutual information often yields better accuracy. Additionally, three identification methods have diverse performance levels, showing their application potentials for different control design algorithms. In contrast, grey-box optimal parameter identification is the most promising for advanced control design considering stability, although its simplified representation of complex mechanical dynamics needs additional dynamic compensation which will be studied in future.


2019 ◽  
Vol 24 ◽  
pp. 100762 ◽  
Author(s):  
Shuang Song ◽  
Xiong Zhang ◽  
Chen Li ◽  
Kai Wang ◽  
Xianzhong Sun ◽  
...  

Mathematics ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 257
Author(s):  
Chenyang Zhang

Aiming at inertial and viscous parameter identification for the Stewart manipulator regardless of the influence of Coulomb friction, a simple and effective dynamical parameter identification method based on wavelet transform and joint velocity analysis is proposed in this paper. Compared with previously known identification methods, the advantages of the new approach are that (1) the excitation trajectory is easy to design, and (2) it can not only identify the inertial matrix, but also the viscous matrix accurately regardless of the influence of Coulomb friction. Comparison is made among the identification method proposed in this paper, another identification method proposed previously, and the true value calculated with a formula. The errors from results of different identification methods demonstrate that the method proposed in this paper shows great adaptability and accuracy.


Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4031 ◽  
Author(s):  
Theodoros Kalogiannis ◽  
Md Hosen ◽  
Mohsen Sokkeh ◽  
Shovon Goutam ◽  
Joris Jaguemont ◽  
...  

A lithium-ion battery cell’s electrochemical performance can be obtained through a series of standardized experiments, and the optimal operation and monitoring is performed when a model of the Li-ions is generated and adopted. With discrete-time parameter identification processes, the electrical circuit models (ECM) of the cells are derived. Over their wide range, the dual-polarization (DP) ECM is proposed to characterize two prismatic cells with different anode electrodes. In most of the studies on battery modeling, attention is paid to the accuracy comparison of the various ECMs, usually for a certain Li-ion, whereas the parameter identification methods of the ECMs are rarely compared. Hence in this work, three different approaches are performed for a certain temperature throughout the whole SoC range of the cells for two different load profiles, suitable for light- and heavy-duty electromotive applications. Analytical equations, least-square-based methods, and heuristic algorithms used for model parameterization are compared in terms of voltage accuracy, robustness, and computational time. The influence of the ECMs’ parameter variation on the voltage root mean square error (RMSE) is assessed as well with impedance spectroscopy in terms of Ohmic, internal, and total resistance comparisons. Li-ion cells are thoroughly electrically characterized and the following conclusions are drawn: (1) All methods are suitable for the modeling, giving a good agreement with the experimental data with less than 3% max voltage relative error and 30 mV RMSE in most cases. (2) Particle swarm optimization (PSO) method is the best trade-off in terms of computational time, accuracy, and robustness. (3) Genetic algorithm (GA) lack of computational time compared to PSO and LS (4) The internal resistance behavior, investigated for the PSO, showed a positive correlation to the voltage error, depending on the chemistry and loading profile.


Author(s):  
Sakya Tripathy ◽  
Edward Berger ◽  
Kumar Vemaganti

There is growing evidence of the importance of mechanical deformations on various facets of cell functioning. This asks for a proper understanding of the cell’s characteristics as a mechanical system in different physiological and mechanical loading conditions. Many researchers use atomic force microscopy (AFM) indentation and the Hertz contact model for elastic material property identification under shallow indentation. For larger indentations, many of the Hertz assumptions are not inherently satisfied and the Hertz model is not directly useful for characterizing nonlinear elastic or inelastic material properties. We have used exponential hyperelastic material in FE simulations of the AFM indentation tests. A parameter identification approach is developed for hyperelastic material property determination from the simulated data. We collected AFM indentation data on agarose gel and developed a simple algorithm for contact point detection. The contact point correction improves the prediction of elastic modulus over the case of visual contact point identification. The modulus of 1% agarose gel was found to be about 15 kPa using the proposed correction, with mild but non-trival hardening with deeper indentation. The experimental data is compared with the results from the FE simulations and shows that over the hardening portion of the indentation response, our proposed parameter identification approach successfully captures the experimental data.


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