Parameterisation of Joints and Constraints for Finite Element Model Updating

1995 ◽  
Author(s):  
Michael I. Friswell ◽  
John E. Mottershead ◽  
Gary H. T. Ng ◽  
Mark G. Smart
Keyword(s):  
Finite Element ◽  
Natural Frequencies ◽  
Model Updating ◽  
Element Model ◽  
Bolted Joints ◽  
Effective Length ◽  
Finite Element Models ◽  
Cantilever Plate ◽  
Rigid Boundary ◽  
Sensitivity Method

Abstract The sensitivity method is applied to update finite element models of welded and bolted joints, and the boundary condition of a cantilever plate. Careful parameterisation is found to be critical in updating the joints and boundary conditions. Updating geometric parameters has considerable potential in updating. The use of nodal offset dimensions results in an updated model of the welded joint with physical interpretation. Similarly the ‘rigid’ boundary in a cantilever plate is successfully updated using the effective length of the elements closest to the joint. In all cases an improvement on the analytical natural frequencies is demonstrated.

Application of a FRF Based Model Updating Technique for the Validation of Finite Element Models of Components of the Automotive Industry

1995 ◽  
Author(s):  
Stefan Lammens ◽  
Marc Brughmans ◽  
Jan Leuridan ◽  
Ward Heylen ◽  
Paul Sas
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Automotive Industry ◽  
Stiffness Matrix ◽  
Model Updating ◽  
Dynamic Stiffness ◽  
Element Model ◽  
Model Parameters ◽  
Finite Element Models ◽  
Analytical Dynamic

Abstract This paper presents two applications of the RADSER model updating technique (Lammens et al. (1995) and Larsson (1992)). The RADSER technique updates finite element model parameters by solution of a linearised set of equations that optimise the Reduced Analytical Dynamic Stiffness matrix based on Experimental Receptances. The first application deals with the identification of the dynamic characteristics of rubber mounts. The second application validates a coarse finite element model of a subframe of a Volvo 480.

Finite Element Model Updating Approach to Damage Identification in Beams Using Particle Swarm Optimization

2008 ◽  
Author(s):  
Mohamed M. Saada ◽  
Mustafa H. Arafa ◽  
Ashraf O. Nassef
Keyword(s):  
Finite Element ◽  
Particle Swarm Optimization ◽  
Finite Element Model ◽  
Natural Frequencies ◽  
Damage Identification ◽  
Model Updating ◽  
Particle Swarm ◽  
Element Model ◽  
Pso Algorithm ◽  
Swarm Optimization

The use of vibration-based techniques in damage identification has recently received considerable attention in many engineering disciplines. While various damage indicators have been proposed in the literature, those relying only on changes in the natural frequencies are quite appealing since these quantities can conveniently be acquired. Nevertheless, the use of natural frequencies in damage identification is faced with many obstacles, including insensitivity and non-uniqueness issues. The aim of this paper is to develop a viable damage identification scheme based only on changes in the natural frequencies and to attempt to overcome the challenges typically encountered. The proposed methodology relies on building a Finite Element Model (FEM) of the structure under investigation. A modified Particle Swarm Optimization (PSO) algorithm is proposed to facilitate updating the FEM in accordance with experimentally-determined natural frequencies in order to predict the damage location and extent. The method is tested on beam structures and was shown to be an effective tool for damage identification.

scholarly journals Structural Optimization Coupled with Materials Selection for Stiffness Improvement

2020 ◽  
Vol 22 (4) ◽  
pp. 831-844
Author(s):  
Hugo Miguel Silva ◽  
José Filipe Meireles ◽  
Jerzy Wojewoda
Keyword(s):  
Finite Element ◽  
Model Updating ◽  
Optimization Procedure ◽  
Element Model ◽  
Finite Element Models ◽  
Materials Selection ◽  
Reinforced Plate ◽  
Selection For ◽  
Geometric Variables ◽  
Matlab Programming

AbstractAn application of a Finite Element Model updating is presented in this paper. Two Finite Element models were considered: a reinforced plate and a thin-walled beam. The two parts were numerically calculated in ANSYS Mechanical APDL and MATLAB programs. ANSYS performs Finite Element calculations, and a MATLAB programming code was used to control the optimization procedure. Geometric variables were chosen, to evaluate the value of the defined objective function. The material was picked using available selection charts, to find the most adequate one for the study. It has been concluded that the transveral displacement of the models modified by the optimization process decreased sharply in relation to the original state.

scholarly journals Application of Optimization Based Finite Element Model Updating Method On 3d Printed Model Structures

2019 ◽  
Author(s):  
Mohammed Kashama Guzunza ◽  
Ozgur Ozcelik ◽  
Umut Yucel ◽  
Ozgur Girgin
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Model Updating ◽  
Complex Structure ◽  
Element Model ◽  
Initial Structure ◽  
Finite Element Models ◽  
3D Printed ◽  
Building System ◽  
Shear Building

Nowadays it becomes trend in studying of dynamic behavior on complex structure. Model updating is one of the tools developed for verifying accuracy of finite element models. In this paper, method for computing model updating on finite element model and effective the experimental modal analysis of structural systems is developed. The identification method developed in this study is based on time-domain system identification numerical techniques. The case study considered in this work is a 3D printed structure that be modeled as a two-story shear building system with irregular torsion. A preliminary numerical model of the two-story shear building system is developed by using SAP2000 and the experimental modal parameters data are collected in the laboratory buy some test then are modeled by Artemis modal pro. After obtaining the results from numerical modal and experimental modal, it was brought to FEMtools software to improve the match between the dynamic properties of an initial structure and the experimentally estimated modal data for updating. After updating, it’s shown that optimization was done, that some unknown material parameters (such as mass density and young modulus) of materials and/or boundary conditions were optimized by FEMtools Optimization that provides the possibility to perform design optimization on updated finite element models.

Analytical and Finite Element Modal Analysis of a Hyperelastic Membrane for Micro Air Vehicle Wings

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
Uttam Kumar Chakravarty
Keyword(s):  
Finite Element ◽  
Natural Frequencies ◽  
Wind Tunnel Test ◽  
Element Model ◽  
Micro Air Vehicle ◽  
Finite Element Models ◽  
Freestream Velocity ◽  
Modal Characteristics ◽  
Aerodynamic Pressure ◽  
Air Vehicle

Analytical and finite element models are developed for investigating the modal characteristics of a hyperelastic rubber latex membrane for micro air vehicle wings applications. A radially prestretched membrane specimen is attached to a thin, rigid circular ring and vibrated in vacuum and in air at atmospheric pressure. The natural frequencies of the membrane computed by analytical and finite element models are correlated well. The natural frequencies increase with mode and prestretch level of the membrane but decrease in air from those in vacuum due to the effect of added mass of air. The damping is low and has a very minimal effect on the frequencies but helps to reduce the amplitude of vibration. Aerodynamic pressure at different angles of attack and a freestream velocity is computed from the wind tunnel test data, and a finite element model is developed for investigating the effect of the aerodynamic pressure on the modal characteristics of the membrane. It is found that the effect of aerodynamic pressure on the natural frequencies of the membrane is not significant.

Finite Element Modeling of Structures With L-Shaped Beams and Bolted Joints

2011 ◽  
Vol 133 (1) ◽  
Author(s):  
K. He ◽  
W. D. Zhu
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Predictive Modeling ◽  
Natural Frequencies ◽  
Model Updating ◽  
Bolted Joints ◽  
Beam Model ◽  
Bolted Connection ◽  
Modeling Approach ◽  
Global Dynamic

Due to bending-torsion coupled vibrations of the L-shaped beams and numerous uncertainties associated with the bolted joints, modeling structures with L-shaped beams and bolted joints is a challenging task. With the recent development of the modeling techniques for L-shaped beams by the authors (He and Zhu, 2009, “Modeling of Fillets in Thin-Walled Beams Using Shell/Plate and Beam Finite Elements,” ASME J. Vibr. Acoust., 131(5), p. 051002), this work focuses on developing new finite element (FE) models for bolted joints in these structures. While the complicated behavior of a single bolted connection can be analyzed using commercial FE software, it is computationally expensive and inefficient to directly simulate the global dynamic response of an assembled structure with bolted joints, and it is necessary to develop relatively simple and accurate models for bolted joints. Three new approaches, two model updating approaches and a predictive modeling approach, are developed in this work to capture the stiffness and mass effects of bolted joints on the global dynamic response of assembled structures. The unknown parameters of the models in the model updating approaches are determined by comparing the calculated and measured natural frequencies. In the predictive modeling approach, the effective area of a bolted connection is determined using contact FE models and an analytical beam model; its associated stiffnesses can also be determined. The models developed for the bolted joints have relatively small sizes and can be easily embedded into a FE model of an assembled structure. For the structures studied, including a three-bay space frame structure with L-shaped beams and bolted joints, and some of its components, the errors between the calculated and measured natural frequencies are within 2% for at least the first 13 elastic modes, and the associated modal assurance criterion values are all over 94%.

The Influence of Experimental Errors on the Correction Parameters of Finite Element Models

1997 ◽  
Author(s):  
Stefan Keye
Keyword(s):  
Finite Element ◽  
Natural Frequencies ◽  
Numerical Models ◽  
Element Model ◽  
Finite Element Models ◽  
Correction Factors ◽  
Modal Data ◽  
Experimental Errors ◽  
Measurement Uncertainties ◽  
The Impact

Abstract A simulation study has been performed on the influence of experimental errors on the accuracy of finite element model corrections. The impact of measurement uncertainties on the sub-structure correction factors, natural frequencies, and mode shape correlation is investigated using simulated modal data. Different numerical models are used to assess the effects of modelization error magnitudes and locations.

Sign in / Sign up

Export Citation Format

Share Document