Journal articles: 'Finite element modal updating'

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Li, Zhi Gang, Ying Chao Li, Shu Qing Wang, and Bin Yang. "Finite Element Model Updating of a Steel Jacket Scale Model." Applied Mechanics and Materials 166-169 (May 2012): 588–92. http://dx.doi.org/10.4028/www.scientific.net/amm.166-169.588.

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In this paper, the finite element model of a steel jacket scale model is updated using modal parameters identified by modal test. Updating parameters are selected based on sensitivity analysis by solving modal energies. And then, a two-steps updating process is carried out using different parameters and the Cross-Model Cross-Mode (CMCM) model updating method is applied in each step. Results indicate that with selection of updating parameters and sensitivity analysis, CMCM method can update the finite element model with physical meanings.

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Tu, Fei. "Application of Sliding Smoothing Method Denoising in Model Updating Damage Identification." Journal of Physics: Conference Series 2185, no. 1 (January 1, 2022): 012014. http://dx.doi.org/10.1088/1742-6596/2185/1/012014.

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Abstract The accuracy of finite element model updating for structural damage identification is easily affected by the noise in the measured modal, so the sliding smoothing method is introduced to reduce the impact of noise. In each iteration step, the sliding smoothing method denoising is applied to the difference between measured modal and simulated modal from the finite element model because the time-frequency characteristic of actual modal is different from noise modal. The modal parameters after denoising are used to construct objective function for modal updating, and the optimal question is solved to determine the stiffness in finite element model. Finally, the stiffness change can indicate the damage position and magnitude. The numerical analysis shows the proposed method can improve the robustness of finite element model updating for the structural damage identification.

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HUMBERT, L., F. THOUVEREZ, and L. JEZEQUEL. "FINITE ELEMENT DYNAMIC MODEL UPDATING USING MODAL THERMOELASTIC FIELDS." Journal of Sound and Vibration 228, no. 2 (November 1999): 397–420. http://dx.doi.org/10.1006/jsvi.1999.2411.

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Zhang, Bao Qiang, Guo Ping Chen, and Qin Tao Guo. "Finite Element Model Updating for Unsymmetrical Damping System with Genetic Algorithm." Applied Mechanics and Materials 166-169 (May 2012): 2999–3003. http://dx.doi.org/10.4028/www.scientific.net/amm.166-169.2999.

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Finite element model updating using incomplete complex modal data for unsymmetrical damping system with genetic algorithm is presented. The genetic algorithm method and finite element model updating based on optimization method using complex modal eigenvalue are introduced. The updating for simulation example about a flexible rotor system which is a typical unsymmetrical damping system is performed using bearing stiffness, bearing damping and diameter moment of inertia parameters. The results show that the maximum error of updated parameters is 0.15% and the objective function of genetic algorithm is 0.0081. The study demonstrates that the finite element model updating method using incomplete complex modal data with genetic algorithm is feasible and effective for unsymmetrical damping system.

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Sun, Kaipeng, Yonghui Zhao, and Haiyan Hu. "Experimental Studies on Finite Element Model Updating for a Heated Beam-Like Structure." Shock and Vibration 2015 (2015): 1–15. http://dx.doi.org/10.1155/2015/143254.

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An experimental study was made for the identification procedure of time-varying modal parameters and the finite element model updating technique of a beam-like thermal structure in both steady and unsteady high temperature environments. An improved time-varying autoregressive method was proposed first to extract the instantaneous natural frequencies of the structure in the unsteady high temperature environment. Based on the identified modal parameters, then, a finite element model for the structure was updated by using Kriging meta-model and optimization-based finite-element model updating method. The temperature-dependent parameters to be updated were expressed as low-order polynomials of temperature increase, and the finite element model updating problem was solved by updating several coefficients of the polynomials. The experimental results demonstrated the effectiveness of the time-varying modal parameter identification method and showed that the instantaneous natural frequencies of the updated model well tracked the trends of the measured values with high accuracy.

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Fouzi, M. S. M., K. M. Jelani, N. A. Nazri, and Mohd Shahrir Mohd Sani. "Finite Element Modelling and Updating of Welded Thin-Walled Beam." International Journal of Automotive and Mechanical Engineering 15, no. 4 (December 24, 2018): 5874–89. http://dx.doi.org/10.15282/ijame.15.4.2018.12.0449.

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This article concentrates on the finite element (FE) modelling approach to model welded thin-walled beam and the adoption of model updating technique to enhance the dynamic characteristic of the FE model. Four different types of element connectors which are RBE2, CBAR, CBEAM and CELAS format are used to construct the FE model of welded structure. Normal mode analysis is performed using finite element analysis (FEA) software, MSC Patran/Nastran to extract the modal parameters (natural frequency and mode shape) of the FE model. The precision of predicted modal parameters obtained from the four models of welded structure are compared with the measured counterparts. The dynamic characteristics of a measured counterpart is obtained through experimental modal analysis (EMA) using impact hammer method with roving accelerometer under free-free boundary conditions. In correlation process, the CBAR model has been selected for updating purposes due to its accuracy in prediction with measured counterparts and contains updating parameters compared to the others. Ahead of the updating process, sensitivity analysis is made to select the most sensitive parameter for updating purpose. Optimization algorithm in MSC Nastran is used in FE model updating process. As a result, the discrepancy between EMA and FEA is managed to be reduced. It shows the percentage of error for updated CBAR model shrinks from 7.85 % to 2.07 % when compared with measured counterpart. Hence, it is found that using FE model updating process provides an efficient and systemic way to perform a feasible FE model in replicating the real structure.

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Marwala, Tshilidzi, and Sibusiso Sibisi. "Finite Element Model Updating Using Bayesian Framework and Modal Properties." Journal of Aircraft 42, no. 1 (January 2005): 275–78. http://dx.doi.org/10.2514/1.11841.

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Chen, Hua-Peng, and Than Soe Maung. "Regularised finite element model updating using measured incomplete modal data." Journal of Sound and Vibration 333, no. 21 (October 2014): 5566–82. http://dx.doi.org/10.1016/j.jsv.2014.05.051.

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Wang, De Jun, Zhi Cheng Tan, Yang Li, and Yang Liu. "Review of the Application of Finite Element Model Updating to Civil Structures." Key Engineering Materials 574 (September 2013): 107–15. http://dx.doi.org/10.4028/www.scientific.net/kem.574.107.

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Structural finite element model (FEM) updating in dynamics usually deemed the measured modal parameters as the goal. By modifying the theoretical FEM, the updated modal parameters obtained by the analytical FEM would finally tend to the testing results. But the own complexity of the civil structure leads the optimization problem of FEM updating to be super-size and high non-linear performance. Moreover, the uncertainty and nonuniformity of the structures, material and the environment effect cause the uncertainty of the updating parameters, even the optimization objective function of FEM updating. These features has brought greater difficulty to the model updating in civil engineering structure, especially for the application field. Therefore, in this paper several kinds of methods for FEM updating would be introduced with the comparison of their advantages, disadvantages and the range of application. At the end of this paper, the problems remained to be solved in FEM updating of civil structures are to be presented.

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Xiao, Tian Yin, Jian Gang Han, and Hong Bo Gao. "Finite Element Model Updating of Space Grid Structures." Advanced Materials Research 243-249 (May 2011): 116–19. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.116.

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The aim of updating models is to generate improved numerical models which may be applied in order to predict actual dynamic behaviors of the structure. The approach of numerical predictions to the behavior of a physical system is limited by the assumptions used in the development of the mathematical model. Model updating is about correcting invalid assumptions by processing vibration test results. Updating by improving the physical meaning of the model requires the application of considerable physical insight in the choice of parameters to update and the arrangement of constraints, force inputs and response measurements in the vibration test. The choice of updating parameters is the most important and the numerical predictions should be sensitive to small changes in the parameters. So methods used in model updating places a demand that the mass, stiffness and damping terms should be based on physically meaningful parameters. Using the structure frequency and local modal shape acquired from structural time-history responses, a model updating method of space grid structures was established in this paper. A numerical example is provided to prove the accuracy of this method. The results show that the method can be effectively used to correct the finite element model of space grid structures.

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McCulloch, C. F., P. Vanhonacker, and E. Dascotte. "Validating and Updating Finite Element Models Using Experimental Measurements of Dynamics." Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 204, no. 1 (January 1990): 45–50. http://dx.doi.org/10.1243/pime_proc_1990_204_208_02.

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A method is proposed for updating finite element models of structural dynamics using the results of experimental modal analysis, based on the sensitivities to changes in physical parameters. The method avoids many of the problems of incompatibility and inconsistency between the experimental and analytical modal data sets and enables the user to express confidence in measured data and modelling assumptions, allowing flexible but automated model updating.

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Wan Iskandar Mirza, W. I. I., M. N. Abdul Rani, M. A. Yunus, B. Athikary, and M. S. M. Sani. "Correlating Finite Element Model of a Car Spot-welded Front-End Module in the Light of Modal Testing Data." International Journal of Automotive and Mechanical Engineering 17, no. 2 (July 9, 2020): 7974–84. http://dx.doi.org/10.15282/ijame.17.2.2020.16.0597.

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Model updating methods can be adopted to improve the correlation level between the finite element model of a spot welded structure and its test model. However, in the presence of contact interfaces in the vicinity of the welded areas, improving the correlation level is problematic and challenging. An approach for correlating the finite element model of a welded structure with contact interfaces using finite element model updating and modal testing is proposed. The proposed approach was tested on a car front-end module structure that consisted of nine components and 76 resistance spot-welded joints used to assemble the components. CWELD and CELAS1 element connectors were used to represent the spot-welded joints and contact interfaces in the finite element modelling and updating. This approach was applied successfully to predict the modal parameters of the car spot-welded front-end module. The total error of the initial finite element model of the structure was reduced from 27.13% to 5.75%. The findings of this work suggest that the proposed approach has a great potential for use in investigating the dynamic behaviour of various spot-welded structures without a significant decline in accuracy.

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Deng, Chang, Shao Wei Hu, and Pei Ying Gu. "Modal Identification and Finite Element Model Updating by Adding Known Masses." Applied Mechanics and Materials 405-408 (September 2013): 808–15. http://dx.doi.org/10.4028/www.scientific.net/amm.405-408.808.

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This paper focus on the model updating of civil structural systems. Traditional modal test method can identify the frequency of the civil structure accurate, but it is difficult to identify the mass-normalized mode shape. By adding a series of known masses to the structure, measuring the frequency of this mass-modified system, and only using this set of frequency data, the mass-normalized mode shape of the structure can be identified. And the model updating method was developed, which constructed an objective function through the frequency of the measurement and the FE model, corrected the FE model's parameters to minimize the objective function. The example was included to show the capabilities of the technique. The finite element model of the fixed-free beam was updated by the dynamic characteristics which was identified from the modal test, the results show that updated results coincided with the experience of the analyst.

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Luo, Haitao, Wei Wang, Jia Fu, and Lichuang Jiao. "Finite Element Model Updating of Satellite Sailboard Based on Sensitivity Analysis." Shock and Vibration 2019 (March 21, 2019): 1–12. http://dx.doi.org/10.1155/2019/4547632.

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The modal analysis of a satellite sailboard finite element model is carried out to accurately investigate the response of a satellite sailboard in a complex loaded space environment through simulation. The basic excitation vibration test of the satellite sailboard is used to perform model matching and a correlation test. Appropriate design variables are selected through sensitivity analysis. Modal analysis data and vibration table excitation test response data are used to modify the finite element model. After optimization, the orthogonality of the simulated vibration mode and experimental vibration mode is good. The low-order frequency errors in the simulation model are less than 5%, the high-order errors are less than 10%, and the modal confidence MAC values are above 0.8. The modal frequency and mode shape are closer to the experimental modal frequency and mode shape, respectively. The simulation and test acceleration response of the modified finite element model of a honeycomb panel are compared under the two conditions of sine sweep and random vibration. The acceleration response curves of reference points are consistent, and amplitude and frequency errors are within acceptable limits. The model updating effect is evident, which provides good reference for research on satellites and other aerospace products.

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Husain, N. Abu, H. Haddad Khodaparast, A. Snaylam, S. James, M. Sharp, G. Dearden, and H. Ouyang. "Modal testing and finite element model updating of laser spot welds." Journal of Physics: Conference Series 181 (August 1, 2009): 012024. http://dx.doi.org/10.1088/1742-6596/181/1/012024.

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Jaishi, Bijaya, and Wei-Xin Ren. "Damage detection by finite element model updating using modal flexibility residual." Journal of Sound and Vibration 290, no. 1-2 (February 2006): 369–87. http://dx.doi.org/10.1016/j.jsv.2005.04.006.

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Chen, HuaPeng, and KongFah Tee. "Structural finite element model updating using incomplete ambient vibration modal data." Science China Technological Sciences 57, no. 9 (August 19, 2014): 1677–88. http://dx.doi.org/10.1007/s11431-014-5619-9.

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Sahin, Abdurrahman, and Alemdar Bayraktar. "Computational finite element model updating tool for modal testing of structures." Structural Engineering and Mechanics 51, no. 2 (July 25, 2014): 229–48. http://dx.doi.org/10.12989/sem.2014.51.2.229.

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Gautier, G., R. Serra, and J. M. Mencik. "Vibratory diagnosis by finite element model updating and operational modal analysis." Mechanics & Industry 14, no. 2 (2013): 145–49. http://dx.doi.org/10.1051/meca/2013055.

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Berger, H., L. Barthe, and R. Ohayon. "Parametric updating of a finite element model from experimental modal characteristics." Mechanical Systems and Signal Processing 4, no. 3 (May 1990): 233–42. http://dx.doi.org/10.1016/0888-3270(90)90017-f.

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Wang, Jutao, Zhenzhong Liu, and Liju Xue. "Structural model updating based on metamodel using modal frequencies." Frattura ed Integrità Strutturale 15, no. 58 (September 25, 2021): 114–27. http://dx.doi.org/10.3221/igf-esis.58.09.

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Modal frequencies are often used in structural model updating based on the finite element model, and metamodel technique is often applied to the corresponding optimization process. In this work, the Kriging model is used as the metamodel. Firstly, the influence of different correlation functions of Kriging model is inspected, and then the approximate capability of Kriging model is investigated via inspecting the approximate accuracy of nonlinear functions. Secondly, a model updating procedure is proposed based on the Kriging model, and the samples for constructing Kriging model are generated via the method of Optimal Latin Hypercube. Finally, a typical frame structure is taken as a case study and demonstrates the feasibility and efficiency of the proposed approach. The results show the Kriging model can match the target functions very well, and the finite element model can achieve accurate frequencies and can reliably predict the frequencies after model updating.

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Ma, Tianzheng, Yimin Zhang, and Xianzhen Huang. "A novel approach for stochastic finite element model updating and parameter estimation." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 228, no. 18 (March 31, 2014): 3329–42. http://dx.doi.org/10.1177/0954406214529945.

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The traditional deterministic finite element updating only deals with a single specified structure. However, it is conceivable that uncertainties such as the geometric tolerances and physical properties of the material, will lead to the variability of the structural behaviors for a panel of nominally identical structures. In this case, we have to resort to the stochastic finite element updating approach to handle the problem. Based on the stochastic perturbation method, a new framework of stochastic finite element updating using data from modal test is proposed in this paper. The efficiency of updating is improved through dividing the updating procedure into two independent parts: the deterministic part updating and the stochastic part updating. The Bayesian statistical method is employed to improve the estimation accuracy of stochastic part updating. Two numerical examples are used to demonstrate the effectiveness and the efficiency of the proposed method.

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Hao, Xiang Wei, and Yang Liu. "Updating the Finite Element Model of a Bridge Model Using a Hybrid Optimization Method." Key Engineering Materials 456 (December 2010): 37–50. http://dx.doi.org/10.4028/www.scientific.net/kem.456.37.

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Finite element model updating of structures usually ends up with a nonlinear optimization problem. An efficient optimization technique is proposed firstly, which draws together the global searching capability of chaos-based optimization technique and high searching efficiency of trust-region Newton method. This hybrid approach is demonstrated to be more efficient and prone to global minimum than conventional gradient search methods and random search methods by testifying with three test functions. The optimization problem for model updating using modal frequencies and modal shapes is formulated, and a procedure to update the boundary support parameters is presented. A modal test was conducted on a beam structure, and the identified mode frequencies are employed to formulate the optimization problem with the support parameters as the updating parameters. The discrepancy between the mode frequencies of the finite element models before and after updating is greatly reduced, and the updated support condition meet quite well with the insight to the devices that form the supports.

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Santos, Filipe, Corneliu Cismaşiu, Ildi Cismaşiu, and Chiara Bedon. "Dynamic Characterisation and Finite Element Updating of a RC Stadium Grandstand." Buildings 8, no. 10 (October 12, 2018): 141. http://dx.doi.org/10.3390/buildings8100141.

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This paper reports on the dynamic characterisation of a Reinforced Concrete (RC) stadium grandstand module for the Sporting Stadium in Lisbon. To this aim, a three-dimensional (3D) Finite-Element (FE) numerical model, implemented according to the technical drawings of the structure, is first presented to provide preliminary estimates of the expected modal characteristics for the examined structural system. Ambient vibration tests are then carried out on the same grandstand, and used to extract the natural frequencies and vibration modes of the system, according to conventional state-of-the-art output-only modal parameter identification techniques. A sensitivity investigation and FE model updating study is hence presented for the grandstand, giving evidence of the major influencing parameters and key input data for the numerical fitting of the experimental modal testing results.

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Chhipa, Sajid Mohammad, Pramod Kumar, Ashok Kumar Bagha, and Shashi Bahl. "Removing fiber orientation uncertainty from the finite element model of a composite lamina with direct updating algorithm." Physica Scripta 96, no. 12 (December 1, 2021): 125040. http://dx.doi.org/10.1088/1402-4896/ac445e.

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Abstract In this paper, a direct updating algorithm is proposed to remove the uncertainties present in the simulated/analytical finite element (FE) model of a composite material lamina. There are number of possible uncertainties present in the composite materials such as its constituent properties and its orientations, boundary conditions and its assumed dimensions etc It is observed from this analytical study that the uncertainty present in the fiber orientation in the matrix put its direct effect on the modal-model (natural frequencies and corresponding mode shapes) of the composite material lamina. The direct updating algorithm has been already used for many isotropic structures. However, for anisotropic structures like composite materials, the application to accurate the simulated-finite element model by using finite element model updating techniques is a new area of research. In this regard, to remove these uncertainties from the simulated-finite element model of a composite lamina, the application of direct updating algorithm is proposed. It is observed from the present study that by updating the mass and the stiffness matrices through direct updating algorithm, the vibration pattern of the mode shapes are updated. It is found that the maximum percentage error in the constituent properties and in the fiber orientation is 22.58% and 100% respectively that are reduced to 0% in the modal-model of the lamina by the application of direct updating algorithm. This represents the novelty of the application of direct updating method for composite lamina structures. The overlay of frequency response function (FRF) curves are plotted to authenticate the results. Also, it is found that the application of the direct updating algorithm increases the tracking performance of the simulated FE model response when excited at different resonant frequencies.

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Altunel, Fatih, Mehmet Çelik, and Mehmet Çalişkan. "A Correlation Improvement Technique for Model Updating of Structures." International Journal of Structural Stability and Dynamics 16, no. 08 (August 25, 2016): 1550049. http://dx.doi.org/10.1142/s0219455415500492.

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This study proposes a new correlation improvement technique for the optimum node removal location to get improved modal assurance criterion (MAC) matrix. The technique is applied to updating of the finite element model (FEM) of a structure. The developed routine is tried on a utility helicopter. It is proven that it is capable of showing better performance than the coordinate MAC (coMAC), commonly used in such analyses. Commercial software is utilized for the finite element analysis of the helicopter fuselage and tail. Experimental modal analyses are also performed for updating the model for tail of the helicopter to demonstrate the effectiveness of the new technique.

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Zárate, Boris A., and Juan M. Caicedo. "Finite element model updating: Multiple alternatives." Engineering Structures 30, no. 12 (December 2008): 3724–30. http://dx.doi.org/10.1016/j.engstruct.2008.06.012.

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Ismail, Z. "Finite Element Model Updating of Reinforced Concrete Beams with Honeycomb Damage." Archives of Civil Engineering 58, no. 2 (June 1, 2012): 135–51. http://dx.doi.org/10.2478/v.10169-012-0008-x.

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Abstract A method of detecting honeycombing damage in a reinforced concrete beam using the finite element model updating technique was proposed. A control beam and two finite element models representing different severity of damage were constructed using available software and the defect parameters were updated. Analyses were performed on the finite element models to approximate the modal parameters. A datum and a control finite element model to match the datum test beams with honeycombs were prepared. Results from the finite element model were corrected by updating the Young’s modulus and the damage parameters. There was a loss of stiffness of 3% for one case, and a loss of 7% for another. The more severe the damage, the higher the loss of stiffness. There was no significant loss of stiffness by doubling the volume of the honeycombs.

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Zhan, Ming, Qintao Guo, Lin Yue, and Baoqiang Zhang. "Modeling and Stochastic Model Updating of Bolt-Jointed Structure." Shock and Vibration 2018 (November 6, 2018): 1–12. http://dx.doi.org/10.1155/2018/8354249.

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Bolt-jointed structure is widely used in engineering fields. The dynamic characteristics of bolt-jointed structure are complex, and there is a variety of uncertainties in the jointed structure. In this study, modeling and updating of a typical bolt-jointed structure are investigated. In modeling terms, three-dimensional brick elements are used to represent the substructures, and thin-layer elements with virtual material properties are employed to represent the joint interface. Modal tests and experimental modal analysis of substructures and built-up structure are performed. A hierarchical model updating strategy based on Bayesian inference is applied to identify the unknown parameters in the substructures model and those in the overall model. Radial basis function (RBF) models are used as surrogates of time-consuming finite element model with high resolution to avoid the enormous computational cost. The results indicate that the updated model can reproduce modal frequencies used in updating and can predict those not used in the updating procedure.

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Arora, Vikas. "Comparative study of finite element model updating methods." Journal of Vibration and Control 17, no. 13 (March 7, 2011): 2023–39. http://dx.doi.org/10.1177/1077546310395967.

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The effects of vibrations present major hazards and operating limitations ranging from discomfort (including noise), malfunctioning, reduced performance, early breakdown and structural failure which, in the worst case can be catastrophic. Hence, accurate mathematical models are required to describe the vibration characteristics of structures, which subsequently can be used for design purposes to limit the negative effects of vibrations. Finite element (FE) predictions are often called into question when they are in conflict with test results. Inaccuracies in FE models and errors in results predicted by them can arise due to the use of incorrect modeling of boundary conditions, incorrect modeling of joints, and difficulties in modeling of damping. This has led to the development of model updating techniques, which aim at reducing the inaccuracies present in an analytical model in the light of measured dynamic test data. In this paper, a detailed comparison of two approaches of obtaining updated FE models are evaluated with the objective that the frequency response functions (FRFs) obtained from updated FE models are able to predict the measured FRFs accurately. In the first method, the updated FE model is obtained by a direct method, which uses modal data. In the second method, the updated model is obtained by an iterative method, which uses FRF data and is also a parameter-based method. The effectiveness of both methods is evaluated by numerical examples, as well as by actual experimental data. Firstly, a study is performed using a numerical simulation based on fixed-fixed beam structure. The numerical study is followed by a case involving actual measured data for the case of an F-shaped test structure. The updated results have shown that the iterative method gives 20% better matching of FRFs with the experimental data and also the predictions of the iterative method is better than the direct method beyond the considered frequency range. The updated results have shown that the FE model obtained using the response function method, an iterative method, can be used to derive accurate model of the system. Updated models obtained by both methods are subsequently evaluated for its application in dynamic design.

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Hiatt, Matthew, Annika Mathiasson, John Okwori, Seung Seop Jin, Shen Shang, Gun Jin Yun, Juan Caicedo, Richard Christenson, Chung Bang Yun, and Hoon Sohn. "Finite Element Model Updating of a PSC Box Girder Bridge Using Ambient Vibration Test." Advanced Materials Research 168-170 (December 2010): 2263–70. http://dx.doi.org/10.4028/www.scientific.net/amr.168-170.2263.

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In this paper, in-field ambient vibration testing of a highway bridge in South Korea under traffic loadings has been conducted to update its finite element model for future predictive analysis and diagnosis purpose. The research results presented in this paper are outcomes from an international REU (Research Experience for Undergraduates) program in smart structures funded by US-NSF (National Science Foundation) and hosted abroad by the Korean Advanced Institute of Science and Technology (KAIST). The monitoring, modeling, and model updating of civil infrastructures are vital in maintaining new design and maintenance standards. Using the frequency domain decomposition (FDD), experimental modal properties of the structure were found and, after a finite element model was created and updated based on the modal properties. From the results, it has been concluded that (a) the FDD method successfully identified the modal characteristics of the structure from ambient vibration, (b) that model updating improved the accuracy of the finite element model, (c) Representing the structural supports as springs in the FEM improved the results from the ideally supported model.

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N.A.Z. Abdullah, M.N.A.M. Asri, and Mohd Shahrir Mohd Sani. "Strategies of Finite Element Modeling for Spot Welded Joints and its Modal Correlation with Experimental Data." International Journal of Automotive and Mechanical Engineering 19, no. 1 (March 24, 2022): 9543–50. http://dx.doi.org/10.15282/ijame.19.1.2022.17.0736.

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In building many complex engineering structures, there are many types of joining methods such as welding and fasteners that can be implemented. Modeling for joints in finite elements can be challenging as it sometimes has limiting factors that cause the prediction of the dynamic behaviour of the actual joints to be less accurate. This study aims to demonstrated several approaches of finite element modeling for spot-welded joints ad to analyse its accuracy through the correlation of modal data from experimental modal analysis. These modeling approaches are created by creating and manipulating the elements at the associated location of the spot weld joint on a top-hat beam structure. Four different approaches of spot weld modeling that uses the modeling strategies performed in other studies were created. The spot weld models are validated by comparing the modal properties of the tested structure which are obtained through finite element analysis and experiments. Model updating was performed on all models in order to observe the ability of model improvement in those different modelling approaches. The findings show that the model that uses solid elements has the lowest error compared to the model that uses beam elements. The model that uses multiple-beam elements shows the ability to be improved the most. The model that uses the simplest modeling approach using a single beam has the highest error and shows the lowest improvement after model updating. It was found that solid element is more suitable to model spot weld and the application of solid element for spot weld joints should be investigated in more types of analyses.

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Abdullah, N. A. Z., M. S. M. Fouzi, and M. S. Mohd Sani. "Computational Modal Analysis on Finite Element Model of Body-in-white Structure and Its Correlation with Experimental Data." International Journal of Automotive and Mechanical Engineering 17, no. 2 (July 7, 2020): 7915–26. http://dx.doi.org/10.15282/ijame.17.2.2020.10.0591.

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Nowadays, computational modelling and simulation are highly popular to increase the efficiency, productivity and shorten the product development period. The quality of a structure also can be determined by using computational analysis such as finite element analysis. Body-in-white structure, as one of the most important structures in the automotive field, has gained a lot of interest as the topic of research. This increase the demand of having a good finite element model of the structure. However, since body-in-white is a highly complicated structure, sometimes modelling simplification cannot be avoided. This study intended to investigate the level of accuracy of the simplified body-in-white model that was modelled by using several modelling strategies. The first body-in-white finite element model was modelled by neglecting the existing joint element in its actual structure. The other body-in-white model includes the joint element by including two different one-dimensional elements to replicate the joining in BIW actual structure. Validation on these body-in-white models are performed by correlating the finite element modal properties with the experimental modal properties. The discrepancies that had surfaced after the correlation was reduced by using a model updating method. The discussed results showed that as the model is under major simplification, several parameters were inaccurately assumed in the initial body-in-white model. Thus, the model updating method has successfully determined the less accurate parameter and the level of discrepancies between the model and experimental data were successfully reduced.

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Sun, Hang, and Yang Liu. "An Improved Taguchi Method and its Application in Finite Element Model Updating of Bridges." Key Engineering Materials 456 (December 2010): 51–65. http://dx.doi.org/10.4028/www.scientific.net/kem.456.51.

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In the model updating process, the objective function is usually set as the weighted sum of the difference between analytical and experimental dynamic characteristics. But it is difficult to select the weighting factors since the relative importance of each parameter to updated results is not obvious but specific for different problem. To overcome this problem, multi-objective genetic algorithm (GA) is introduced into model updating by Gyeong-Ho Kim since there is no need for selecting weighting values in multi-objective optimization technique. To complex structures, however, it is difficult to update the structural models by GA because of the relative low efficiency. While Taguchi updating method, deemed as an efficient and robust method, is a good choice to update the models of large structures. But Taguchi method is only applied to solve the single objective optimization problem of model updating. Therefore, this paper proposed improved Taguchi updating method to deal with the problem of model updating using multi-objective optimization technique. Then the proposed method is applied to update the model of a 14-bay beam with measured frequencies and modal shapes. The updated results show that the proposed method is promising to structural model updating.

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Hu, Chang Lin, Li Yuan Ma, Yong Jun Li, and Hui Li. "Modal Parameter Simulation and Model Updating for some Launch Platform." Advanced Materials Research 490-495 (March 2012): 1009–13. http://dx.doi.org/10.4028/www.scientific.net/amr.490-495.1009.

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The frequencies and vibration modes of a launch platform are acquired through finite element simulation, and their actual values are obtained through modal test. On this basis, constructing objective function for the structure modal parameter relative residual error to be minimum, can transform model updating problem into optimization problem. Then the trust region algorithm is adopted to solve this optimization problem. This algorithm bears better robustness and computing efficiency. Through model updating, the frequency and vibration mode errors are reduced, supplying a basis for further simulation.

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Wang, Li Xian, and Sheng Kui Di. "Dynamic Test and Analysis of Double Curved Arch Bridge Based on Ambient Excitation." Advanced Materials Research 671-674 (March 2013): 1021–24. http://dx.doi.org/10.4028/www.scientific.net/amr.671-674.1021.

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Dynamic test of double curved arch bridge based on environmental incentives. And Peak value method stochastic subspace identification method is used for modal analysis, and bridge modal parameters are obtained. The results were compared with the finite element software Midas civil, and results are consistent. The test shows that the bridge modal parameters can be identified in the environmental stimulus response. Measured frequency is lower than the finite element calculation of frequency; it means the bridge stiffness is lower. The identified dynamic properties can be served as the basis in the finite element model updating, damage detection, condition assessment and health monitoring of the bridge.

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Liu, Xun Tao, Zhao Bo Chen, and Shan Yun Huang. "The Study of Spacecraft Finite Element Model Updating System." Applied Mechanics and Materials 121-126 (October 2011): 4852–57. http://dx.doi.org/10.4028/www.scientific.net/amm.121-126.4852.

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with the development of finite element technology, finite element model is becoming to the main analysis tool. However, because some theoretic assumptions, unsuitable constraint and uncertain material property are applied, the simulation result of finite element model isn’t different from the testing data. In order to improve the design quality and safety of spacecraft, this paper deduced the formula of spacecraft finite element updating, developed the spacecraft finite element model updating system, the software mainly of five parts: the frequency response function calculation, the loading inverse solution, the finite element model updating, the data display, virtual experimentation. Software can complete exciting force inverse, parameter sensitivity analysis, parameters screening and finite element model updating. The calculation result of updated finite element model is in accordance with testing curve shape on the main vibration direction, first-order frequency error is ±5%, response error is ±10%. Software meet the need of finite element model updating, it provide a software base for spacecraft design.

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Argyris, Costas, Costas Papadimitriou, Panagiotis Panetsos, and Panos Tsopelas. "Bayesian Model-Updating Using Features of Modal Data: Application to the Metsovo Bridge." Journal of Sensor and Actuator Networks 9, no. 2 (June 3, 2020): 27. http://dx.doi.org/10.3390/jsan9020027.

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A Bayesian framework is presented for finite element model-updating using experimental modal data. A novel likelihood formulation is proposed regarding the inclusion of the mode shapes, based on a probabilistic treatment of the MAC value between the model predicted and experimental mode shapes. The framework is demonstrated by performing model-updating for the Metsovo bridge using a reduced high-fidelity finite element model. Experimental modal identification methods are used in order to extract the modal characteristics of the bridge from ambient acceleration time histories obtained from field measurements exploiting a network of reference and roving sensors. The Transitional Markov Chain Monte Carlo algorithm is used to perform the model updating by drawing samples from the posterior distribution of the model parameters. The proposed framework yields reasonable uncertainty bounds for the model parameters, insensitive to the redundant information contained in the measured data due to closely spaced sensors. In contrast, conventional Bayesian formulations which use probabilistic models to characterize the components of the discrepancy vector between the measured and model-predicted mode shapes result in unrealistically thin uncertainty bounds for the model parameters for a large number of sensors.

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Chen, Xue Qian, Shi Fu Xiao, and Xin En Liu. "The Finite Element Model (FEM) Updating of Mirror Frame System Based on Response Surface Method." Advanced Materials Research 291-294 (July 2011): 1615–20. http://dx.doi.org/10.4028/www.scientific.net/amr.291-294.1615.

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It is difficult in finite element model(FEM) updating, because the essence is a mechanical anti-question solving. In the paper, the suppositional material method is utilized to model the FEM of a mirror frame system, and the required updating parameters are defined. The functions between the natural frequency and the updating parameters are established based on the response surface method. Based on the response surface model and the modal experiment results, the sum of absolute value of relative errors between the results of experiments and simulations is defined as the optimization objective, four required updating are identified automatically. The first three natural frequencies of updated mirror frame system are better accordant with the experiment results, which proves the method correct and reliable.

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Park, Wonsuk. "On-line Finite Element Model Updating Using Operational Modal Analysis and Neural Networks." Journal of the Computational Structural Engineering Institute of Korea 34, no. 1 (February 1, 2021): 35–42. http://dx.doi.org/10.7734/coseik.2021.34.1.35.

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Calayır, Yusuf, Musa Yetkin, and Hakan Erkek. "Finite element model updating of masonry minarets by using operational modal analysis method." Structures 34 (December 2021): 3501–7. http://dx.doi.org/10.1016/j.istruc.2021.09.103.

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Hosseinlou, F., A. Mojtahedi, and M. A. Lotfollahi. "Finite Element Model Updating of an Offshore Jacket Platforms using Experimental Modal Analysis." Journal of Computational Methods In Engineering 36, no. 1 (September 1, 2017): 67–96. http://dx.doi.org/10.18869/acadpub.jcme.36.1.67.

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Kompalka, A. S., and S. Reese. "Finite Element Model Updating for Damage Localisation and Quantification Using Experimental Modal Data." Key Engineering Materials 293-294 (September 2005): 297–304. http://dx.doi.org/10.4028/www.scientific.net/kem.293-294.297.

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In this contribution we present a validation of an identification procedure and a modeling method with regard to detection, localisation and quantification of damage in a structure. Vibration measurements of an excited experimental structure are used as input for a stochastic subspace system identification algorithm. The identified experimental modal data (eigenvalues and mode shapes) serve to update the underlying finite element model. The experimental setup consists of a cantilever beam and an additional equipment to damage the structure locally and progressively. In contrast to earlier contributions the evolution of damage is quantified in order to estimate the lifetime of the structure.

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David-West, O. S., J. Wang, and R. Cooper. "Model Updating of an Enclosure Using Imaginary Elements." Applied Mechanics and Materials 70 (August 2011): 309–14. http://dx.doi.org/10.4028/www.scientific.net/amm.70.309.

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This study was of two phases, one aspect tailored towards matching of the natural frequencies between experimental and finite element results and the second, focused on the effect of damping on the frequency response functions. The experimental Modal Analysis was performed on the real structure to characterize the dynamic behavior in terms of modes, natural frequency and damping using Bruel and Kjaer software. The base of the enclosure was clamped and could be an area of energy dissipation and a source of damping. This boundary condition was model with imaginary joint elements. The dynamic analysis was realized using the Lanczos tool in ANSYS 12 finite element code to extract the modes and also harmonic response analysis was conducted to get the response functions. The linear and rotational stiffness of the boundaries and structural stiffness of the panels were used as updating parameters, tailored towards minimisation of the percentage error in the natural frequencies. The inclusion of damping reduced the amplitude of vibration.

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Zhang, Yu Xin, Zeng Zhong Wang, and Ye Yan Liu. "Strain Measurements Based Finite Element Model Updating." Advanced Materials Research 378-379 (October 2011): 98–101. http://dx.doi.org/10.4028/www.scientific.net/amr.378-379.98.

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Analytical models of the actual structure often differ greatly from their as-built counterparts. Model updating techniques improve the predictions of the behavior of the actual structure by identifying and correcting the uncertain parameters of the analytical model. This paper presents a new model updating technique to improve the finite element analysis model by updating design parameters using strain measurement based on affine scaling interior Algorithm. Static strain measurements are more reliable and realistic than acceleration data in practice. Numerical examples are presented to study the application of the method.

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Gladwell, G. M. L., and H. Ahmadian. "Generic element matrices suitable for finite element model updating." Mechanical Systems and Signal Processing 9, no. 6 (November 1995): 601–14. http://dx.doi.org/10.1006/mssp.1995.0045.

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Verma, Shivam, Saurabh Kango, Ashok Kumar Bagha, and Shashi Bahl. "Finite element model updating of smart structures with direct updating algorithm." Physica Scripta 97, no. 5 (April 18, 2022): 055702. http://dx.doi.org/10.1088/1402-4896/ac64d3.

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Abstract In this paper, a finite element model updating algorithm is proposed to enhance the accuracy of the simulated finite element model of a smart structure (collocated piezoelectric patches embedded on a cantilever beam). Piezoelectric patches are used to sense and control the excessive vibrations of the structures. Mostly, they are mounted on flexible structures to measure their response at different excitations. The finite element method can be used to model the beam embedded with collocated piezoelectric patches. The complete finite element formulation of the smart structure is briefly described in this paper. There are different types of uncertainties that may be present in the simulated finite element model of a smart structure such as uncertainty in the structural boundary conditions, in the material elastic properties, the dimensions of the structure, piezoelectric elastic and electric properties, and the location of the piezoelectric patches mounted on the structure. In the present analytical study, the above uncertainties present in the smart structure are reduced by using the direct updating algorithm. It is found that the direct updating method through updating the mass and the stiffness matrices of the smart structure successfully enhance the accuracy of the simulated finite element model of the beam embedded with PZT patches. The state-space method is used to predict the response in the frequency domain. The maximum percentage error in the simulated finite element model of the piezoelectric embedded beam structure due to its structural and the electrical property uncertainty is 10.36% and 23.52% respectively and that was completely removed by using the direct updating algorithm. The optimal location of the piezoelectric patches is also taken as uncertainty which is successfully updated by using the proposed direct updating algorithm. The maximum percentage error in the natural frequencies of the smart structure due to location uncertainty is 18.39% which was also completely removed. To validate the outcomes, a frequency response function (FRF) is plotted.

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Noever-Castelos, Pablo, David Melcher, and Claudio Balzani. "Model updating of a wind turbine blade finite element Timoshenko beam model with invertible neural networks." Wind Energy Science 7, no. 2 (March 16, 2022): 623–45. http://dx.doi.org/10.5194/wes-7-623-2022.

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Abstract. Digitalization, especially in the form of a digital twin, is fast becoming a key instrument for the monitoring of a product's life cycle from manufacturing to operation and maintenance and has recently been applied to wind turbine blades. Here, model updating plays an important role for digital twins, in the form of adjusting the model to best replicate the corresponding real-world counterpart. However, classical updating methods are generally limited to a reduced parameter space due to low computational efficiency. Moreover, these approaches most likely lack a probabilistic evaluation of the result. The purpose of this paper is to extend a previous feasibility study to a finite element Timoshenko beam model of a full blade for which the model updating process is conducted through the novel approach with invertible neural networks (INNs). This type of artificial neural network is trained to represent an inversion of the physical model, which in general is complex and non-linear. During the updating process, the inverse model is evaluated based on the target model's modal responses. It then returns the posterior prediction for the input parameters. In advance, a global sensitivity study will reduce the parameter space to a significant subset on which the updating process will focus. The finally trained INN excellently predicts the input parameters' posterior distributions of the proposed generic updating problem. Moreover, intrinsic model ambiguities, such as material densities of two closely located laminates, are correctly captured. A robustness analysis with noisy response reveals a few sensitive parameters, though most can still be recovered with equal accuracy. And, finally, after the resimulation analysis with the updated model, the modal response perfectly matches the target values. Thus, we successfully confirmed that INNs offer an extraordinary capability for structural model updating of even more complex and larger models of wind turbine blades.

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Min, Cheon-Hong, Jong-Su Choi, Sup Hong, Hyung-Woo Kim, and Tae-Kyeong Yeu. "Damage Detection Using Finite Element Model Updating." Journal of Ocean Engineering and Technology 26, no. 5 (October 31, 2012): 11–17. http://dx.doi.org/10.5574/ksoe.2012.26.5.011.

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Asma, F. "Finite element model updating using Lagrange interpolation." Mechanics and Mechanical Engineering 23, no. 1 (July 10, 2019): 228–32. http://dx.doi.org/10.2478/mme-2019-0030.

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Abstract In this paper, an iterative finite element model updating method in structural dynamics is proposed. This uses information matrices and element connectivity matrices to reconstruct the corrected model by reproducing the frequency response at measured degrees of freedom. Indicators have been proposed to quantify the mismodelling errors based on a development in Lagrange matrix interpolation. When applied on simulated truss structures, the model gives satisfactory results by detecting and quantifying the defaults of the initial model.

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Journal articles on the topic 'Finite element modal updating'

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