Sensitivity Analysis of the Transfer Impedance of Shielded Cables with Braided Shields Using a Parametrized FEM Model

Sensitivity analysis of beams and frames assembled of thin‐walled members is presented within the adjoint approach. Static loads and structures composed of thin‐walled members with the bisymmetrical open cross‐section are considered. The analysed structure is represented by the one‐dimensional model consisting of thin‐walled beam elements based on the classical assumptions of the theory of thin‐walled beams of non‐deformable cross‐section together with superelements applied in place of location of structure nodes, restraints and stiffeners. The results of sensitivity analysis, obtained for the structure model described above, are compared with the results of the detailed FEM model, where the whole structure is discretised with the use of QUAD4 shell elements of the system MSC/NASTRAN.

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Sensitivity analysis of shoulder joint muscles by using the FEM model

Biomaterials and Biomechanics in Bioengineering ◽

10.12989/bme.2016.3.2.115 ◽

2016 ◽

Vol 3 (2) ◽

pp. 115-127

Author(s):

Shriniwas.S. Metan ◽

G.C. Mohankumar ◽

Prasad Krishna

Keyword(s):

Sensitivity Analysis ◽

Shoulder Joint ◽

Fem Model

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Sensitivity analysis of respiratory parameter uncertainties: impact of criterion function form and constraints

Journal of Applied Physiology ◽

10.1152/jappl.1990.69.2.766 ◽

1990 ◽

Vol 69 (2) ◽

pp. 766-775 ◽

Cited By ~ 5

Author(s):

K. R. Lutchen

Keyword(s):

Sensitivity Analysis ◽

Input Impedance ◽

Element Model ◽

Confidence Regions ◽

Alternative Methods ◽

Function Form ◽

Parameter Uncertainties ◽

Criterion Function ◽

Transfer Impedance ◽

Impedance Data

A sensitivity analysis based on weighted least-squares regression is presented to evaluate alternative methods for fitting lumped-parameter models to respiratory impedance data. The goal is to maintain parameter accuracy simultaneously with practical experiment design. The analysis focuses on predicting parameter uncertainties using a linearized approximation for joint confidence regions. Applications are with four-element parallel and viscoelastic models for 0.125- to 4-Hz data and a six-element model with separate tissue and airway properties for input and transfer impedance data from 2-64 Hz. The criterion function form was evaluated by comparing parameter uncertainties when data are fit as magnitude and phase, dynamic resistance and compliance, or real and imaginary parts of input impedance. The proper choice of weighting can make all three criterion variables comparable. For the six-element model, parameter uncertainties were predicted when both input impedance and transfer impedance are acquired and fit simultaneously. A fit to both data sets from 4 to 64 Hz could reduce parameter estimate uncertainties considerably from those achievable by fitting either alone. For the four-element models, use of an independent, but noisy, measure of static compliance was assessed as a constraint on model parameters. This may allow acceptable parameter uncertainties for a minimum frequency of 0.275-0.375 Hz rather than 0.125 Hz. This reduces data acquisition requirements from a 16- to a 5.33- to 8-s breath holding period. These results are approximations, and the impact of using the linearized approximation for the confidence regions is discussed.

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Numerical Modelling of Structures with Uncertainties

Polish Maritime Research ◽

10.1515/pomr-2017-0030 ◽

2017 ◽

Vol 24 (s1) ◽

pp. 125-132 ◽

Cited By ~ 2

Author(s):

Maciej Kahsin

Keyword(s):

Sensitivity Analysis ◽

Modal Analysis ◽

Complex Structure ◽

Offshore Wind ◽

Laboratory Model ◽

Offshore Wind Turbine ◽

Surface Model ◽

Model Parameters ◽

Fem Model ◽

Supporting Structure

Abstract The nature of environmental interactions, as well as large dimensions and complex structure of marine offshore objects, make designing, building and operation of these objects a great challenge. This is the reason why a vast majority of investment cases of this type include structural analysis, performed using scaled laboratory models and complemented by extended computer simulations. The present paper focuses on FEM modelling of the offshore wind turbine supporting structure. Then problem is studied using the modal analysis, sensitivity analysis, as well as the design of experiment (DOE) and response surface model (RSM) methods. The results of modal analysis based simulations were used for assessing the quality of the FEM model against the data measured during the experimental modal analysis of the scaled laboratory model for different support conditions. The sensitivity analysis, in turn, has provided opportunities for assessing the effect of individual FEM model parameters on the dynamic response of the examined supporting structure. The DOE and RSM methods allowed to determine the effect of model parameter changes on the supporting structure response.

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Axial and Pressure Thrust Stiffness of Metal Bellows for Vibration Isolators

MATEC Web of Conferences ◽

10.1051/matecconf/201815306001 ◽

2018 ◽

Vol 153 ◽

pp. 06001 ◽

Cited By ~ 2

Author(s):

Macháček Ondřej ◽

Kubík Michal ◽

Strecker Zbyněk ◽

Roupec Jakub ◽

Novák Petr ◽

...

Keyword(s):

Sensitivity Analysis ◽

Dynamic Behaviour ◽

Axial Stiffness ◽

Axial Deformation ◽

Fem Model ◽

Vibration Isolators ◽

Spring Element ◽

Metal Bellows ◽

Dimensional Parameters ◽

Dimension Parameter

Metal bellows are used as a spring element and simultaneously as a container (shell) for a damping medium in vibration isolators, especially in applications where any leakage is inadmissible. Dynamic behaviour of these isolators is affected by axial stiffness of bellows and by a resistance against axial deformation of bellows filled with fluid, which is in this article called pressure thrust stiffness. A method of the pressure thrust stiffness determination is discussed in this study. The method uses FEM model, which has been verified by stiffness measurement of a chosen bellows. Consequently, the sensitivity analysis of bellows dimensions to axial and pressure thrust stiffness was performed to find a dimension parameter of bellows which allows to adjust the ratio between axial and pressure thrust stiffness. Sensitivity analysis shows that the stiffness ratio of metal bellows can be adjusted by two dimensional parameters - mean diameter of bellows and corrugation width.

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The Analysis of Static and Dynamic Characteristics of Motorized High-Speed Spindle Based on Sensitivity Analysis of FEM Model

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.43.376 ◽

2010 ◽

Vol 43 ◽

pp. 376-381

Author(s):

Song Mei Yuan ◽

Mao Bin Lv ◽

Xue Hao Liu

Keyword(s):

Sensitivity Analysis ◽

Objective Function ◽

Natural Frequency ◽

Dynamic Characteristics ◽

High Speed ◽

Design Sensitivity ◽

Design Parameters ◽

Static Stiffness ◽

Fem Model ◽

Static And Dynamic Characteristics

In order to estimate the static and dynamic characteristics of motorized high-speed spindle, the full parameterized FEM model of it is established and studied in the paper. After the FEM analysis of the spindle, the static stiffness, natural frequency and normal modes of vibration are obtained. Then, a design sensitivity analysis of some design parameters is conducted based on the finite element model to investigate their influence on the static stiffness and natural frequency of the spindle system. Through the sensitivity analysis, the optimal plan is proposed, the first natural frequency as the first objective function of optimization and the static stiffness as the second, which changes the objective function of multivariable into that of a single one. Therefore, it considerably increases the efficiency of optimization. The optimization leads to a noticeable improvement of static stiffness and first-mode natural frequency.

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