Tuning of Finite Element Model Parameters to Match Nonlinear Reduced Order Models

2020 ◽  
pp. 113-116
Author(s):  
Kyusic Park ◽  
Matthew S. Allen
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Model Parameters ◽  
Reduced Order Models ◽  
Reduced Order

scholarly journals Approaches for Reduced-Order Modeling of Electrically Actuated von-Karman Microplates

2016 ◽  
Vol 12 (1) ◽  
Author(s):  
Shahid Saghir ◽  
M.I. Younis
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Electrostatic Force ◽  
Element Model ◽  
Reduced Order Models ◽  
Reduced Order ◽  
Linear Eigenvalue Problem ◽  
Von Karman ◽  
Wide Range ◽  
Von Kármán

This article presents and compares different approaches to develop reduced-order models for the nonlinear von-Karman rectangular microplates actuated by nonlinear electrostatic forces. The reduced-order models aim to investigate the static and dynamic behavior of the plate under small and large actuation forces. A fully clamped microplate is considered. Different types of basis functions are used in conjunction with the Galerkin method to discretize the governing equations. First, we investigate the convergence with the number of modes retained in the model. Then for validation purpose, a comparison of the static results is made with the results calculated by a nonlinear finite element model. The linear eigenvalue problem for the plate under the electrostatic force is solved for a wide range of voltages up to pull-in. Results among the various reduced-order modes are compared and are also validated by comparing to results of the finite-element model. Further, the reduced-order models are employed to capture the forced dynamic response of the microplate under small and large vibration amplitudes. Comparison of the different approaches is made for this case.

scholarly journals Non-Linear Modeling of Centrifugal Stiffening Effects for Accurate Bladed Component Reduced-Order Models

2017 ◽  
Author(s):  
Elias Khalifeh ◽  
Elsa Piollet ◽  
Antoine Millecamps ◽  
Alain Batailly
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Angular Speed ◽  
Reduced Order Models ◽  
Order Model ◽  
Reduced Order ◽  
Linear Finite Element ◽  
Centrifugal Stiffening ◽  
Blade Tip

The modeling of centrifugal stiffening effects on bladed components is of primary importance in order to accurately capture their dynamics depending on the rotor angular speed. Centrifugal effects impact both the stiffness of the component and its geometry. In the context of the small perturbation framework, when considering a linear finite element model of the component, an assumption typically made in the scientific literature involves a fourth-order polynomial development of the stiffness matrix in terms of the angular speed. This polynomial development may fail to provide an accurate representation of the geometry evolution of a blade. Indeed, the error on the blade-tip displacement associated to the use of a linear finite element model quickly reaches the same order of magnitude as the blade-tip/casing clearance itself thus yielding a 100 % error on the blade-tip/casing clearance configuration. This article focuses on the presentation of a methodology that allows for creating accurate reduced order models of a 3D finite element model accounting for centrifugal stiffening with a very precise description of the blade-tip/casing clearance configuration throughout a given angular speed range. The quality of the obtained reduced order model is underlined before its numerical behaviour in the context of non-linear dynamic simulations be investigated. It is evidenced that the new reduced order model features specific interactions that could not be predicted with a linear model. In addition, results highlight the limitations of numerical predictions made for high angular speeds with a linear model. Finally, a particular attention is paid to the numerical sensitivity of the proposed model. As a downside of its increased accuracy, it is underlined that its computation must be done carefully in order to avoid numerical instabilities.

An Effective Method for Determining Finite Element Model Parameters of Rotor Elastic Support System

2011 ◽  
Vol 141 ◽  
pp. 191-197
Author(s):  
Yong Xing Wang ◽  
Jiang Yan ◽  
Sheng Ze Wang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Support System ◽  
Structural Parameters ◽  
Element Model ◽  
Elastic Support ◽  
Asymmetric Structure ◽  
Model Parameters ◽  
Equivalent Stiffness ◽  
Rolling Ball

A finite element model of the elastic support rotor system based on the corresponding experimental model was established. According to the principle of two types of model with an equal first order critical speed, the equivalent stiffness and damping of a rolling ball bearing support system with rubber rings determined by experiment were transferred into the finite element model. Then, the dynamic behavior of rotor systems with symmetric and asymmetric structure, different support system stiffness and support span were calculated and analyzed respectively. At last, the influence of the rotor structural parameters on the equivalent stiffness of elastic bearing support system obtained by experiment was pointed out.

Numerical and Experimental Analysis of Self Piercing Riveting Process with Carbon Fiber-Reinforced Plastic and Aluminium Sheets

2013 ◽  
Vol 554-557 ◽  
pp. 1045-1054 ◽  
Author(s):  
Welf Guntram Drossel ◽  
Reinhard Mauermann ◽  
Raik Grützner ◽  
Danilo Mattheß
Keyword(s):  
Finite Element ◽  
Carbon Fiber ◽  
Finite Element Model ◽  
Simulation Model ◽  
Process Parameters ◽  
Process Model ◽  
Element Model ◽  
Model Parameters ◽  
Fiber Reinforced ◽  
Carbon Fiber Reinforced

In this study a numerical simulation model was designed for representing the joining process of carbon fiber-reinforced plastics (CFRP) and aluminum alloy with semi-tubular self-piercing rivet. The first step towards this goal is to analyze the piercing process of CFRP numerical and experimental. Thereby the essential process parameters, tool geometries and material characteristics are determined and in finite element model represented. Subsequently the finite element model will be verified and calibrated by experimental studies. The next step is the integration of the calibrated model parameters from the piercing process in the extensive simulation model of self-piercing rivet process. The comparison between the measured and computed values, e.g. process parameters and the geometrical connection characteristics, shows the reached quality of the process model. The presented method provides an experimental reliable characterization of the damage of the composite material and an evaluation of the connection performances, regarding the anisotropic property of CFRP.

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.

Bodner-Partom Constitutive Model and Nonlinear Finite Element Analysis

1990 ◽  
Vol 112 (3) ◽  
pp. 287-291 ◽  
Author(s):  
F. A. Kolkailah ◽  
A. J. McPhate
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Plastic Strain ◽  
Constitutive Model ◽  
Finite Element Model ◽  
Numerical Technique ◽  
Element Model ◽  
Material Behavior ◽  
Model Parameters ◽  
Elastic Plastic

In this paper, results from an elastic-plastic finite-element model incorporating the Bodner-Partom model of nonlinear time-dependent material behavior are presented. The parameters in the constitutive model are computed from a leastsquare fit to experimental data obtained from uniaxial stress-strain and creep tests at 650°C. The finite element model of a double-notched specimen is employed to determine the value of the elastic-plastic strain and is compared to experimental data. The constitutive model parameters evaluated in this paper are found to be in good agreement with those obtained by the other investigators. However, the parameters determined by the numerical technique tend to give response that agree with the data better than do graphically determined parameters previously used. The calculated elastic-plastic strain from the model agreed well with the experimental strain.

STRAIN GRADIENT POLYCRYSTAL PLASTICITY ANALYSIS: FE MODELING AND SYNCHROTRON X-RAY DIFFRACTION

2010 ◽  
Vol 24 (01n02) ◽  
pp. 10-17 ◽  
Author(s):  
XU SONG ◽  
SHU YAN ZHANG ◽  
ALEXANDER M. KORSUNSKY
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Strain Gradient ◽  
Deformation Behaviour ◽  
Element Model ◽  
Model Parameters ◽  
Multiple Peaks ◽  
X Ray ◽  
Polycrystal Plasticity ◽  
Meso Scale

The results of a strain gradient finite element model of polycrystalline plastic deformation in an HCP alloy were analysed in terms of orientation-related meso-scale grain groups. The predictions for meso-scale elastic strains were post-processed to construct energy dispersive diffraction peak patterns. Synchrotron X-ray polycrystalline diffraction was thereafter employed to record experimentally multiple peaks from deformed samples of Ti -6 Al -4 V alloy. Model parameters were adjusted to provide the best simultaneous match to multiple peaks in terms of intensity, position and shape. The framework provides a rigorous means of validating polycrystal plasticity finite element model. The study represents an example of the parallel development of modelling and experimental tools that is useful for the study of statistically stored dislocations (SSDs) and geometrically necessary dislocations (GNDs) effects on the deformation behaviour of (poly)crystals.

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