Identification of a reference mathematical model of an arch bridge using full-scale forced modal testing and finite-element modeling

1996 ◽  
Author(s):  
Stanislaw J. Pietrzko ◽  
R. Cantieni ◽  
Y. Deger
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Finite Element Modeling ◽  
Full Scale ◽  
Modal Testing ◽  
Arch Bridge ◽  
Element Modeling

Tire Vibration Modes and Effects on Vehicle Ride Quality

1993 ◽  
Vol 21 (1) ◽  
pp. 23-39 ◽  
Author(s):  
R. W. Scavuzzo ◽  
T. R. Richards ◽  
L. T. Charek
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Operating Conditions ◽  
Modal Testing ◽  
Ride Quality ◽  
Vibration Modes ◽  
Inflation Pressure ◽  
Passenger Cars ◽  
Element Modeling ◽  
Road Surfaces

Abstract Tire vibration modes are known to play a key role in vehicle ride, for applications ranging from passenger cars to earthmover equipment. Inputs to the tire such as discrete impacts (harshness), rough road surfaces, tire nonuniformities, and tread patterns can potentially excite tire vibration modes. Many parameters affect the frequency of tire vibration modes: tire size, tire construction, inflation pressure, and operating conditions such as speed, load, and temperature. This paper discusses the influence of these parameters on tire vibration modes and describes how these tire modes influence vehicle ride quality. Results from both finite element modeling and modal testing are discussed.

Full-scale finite element modeling and nonlinear bending analysis of sandwich plates with functionally graded auxetic 3D lattice core

2020 ◽  
pp. 109963622092465 ◽  
Author(s):  
Chong Li ◽  
Hui-Shen Shen ◽  
Hai Wang
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Plate Thickness ◽  
Functionally Graded ◽  
Full Scale ◽  
Sandwich Plates ◽  
Nonlinear Bending ◽  
Element Modeling ◽  
Bending Load ◽  
Lattice Core

This paper investigates the nonlinear bending behavior of sandwich plates with functionally graded auxetic 3D lattice core. First and foremost, an auxetic 3D lattice metamaterial with negative effective Poisson’s ratio (EPR) is designed and examined via theoretical and finite element methods with experimental verifications using specimens fabricated by 3D printing. Furthermore, three functionally graded configurations of the auxetic 3D lattice core through the plate thickness direction are proposed and compared with the uniform distribution case. Full-scale finite element modeling and nonlinear thermal-mechanical analysis are performed for the sandwich plates, with the temperature-dependent material properties of both core and face sheets taken into account. Numerical results revealed that the auxetic core can remarkably reduce the lateral deflections, with comparison to their non-auxetic counterpart with positive EPR. Parametric studies are further carried out to demonstrate the effects of functionally graded configurations, temperature rises, facesheet-to-core thickness ratios, boundary conditions, and strut radii on the nonlinear bending load-deflection curves, along with EPR-deflection curves in the large deflection region.

scholarly journals Mathematical model of acoustic characteristics of polyurethane foam used for sound absorption in aerospace engineering

2021 ◽  
Vol 20 (2) ◽  
pp. 53-62
Author(s):  
A. V. Kuznetsov ◽  
A. A. Igolkin ◽  
A. I. Safin ◽  
A. O. Pantyushin
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Absorption Coefficient ◽  
Finite Element Modeling ◽  
Sound Absorption ◽  
Sound Absorption Coefficient ◽  
Sound Insulation ◽  
Space Technology ◽  
Acoustic Characteristics ◽  
Element Modeling

When solving the problem of reducing the acoustic load on the spacecraft during the launch and flight of the launch vehicle, finite element modeling of acoustic processes under the nose fairing is carried out. To successfully solve this problem, a mathematical model of the acoustic characteristics of the material used for sound insulation is required. The existing mathematical models of the acoustic characteristics of materials are not suitable for the material under consideration that can be used in rocket and space technology to increase the sound insulation of the payload fairing + transfer compartment assembly. To obtain the sound absorption coefficient of the material, an impedance tube measurement method with two microphones is used. Using the method of differential evolution, the coefficients of a mathematical model of acoustic characteristics of the Delany-Bazley type for the specified material are selected. The sound absorption coefficient obtained experimentally and that calculated using the obtained model are compared; the average and maximum values of the error are shown. The resulting model will make it possible to carry out finite element modeling of acoustic and vibroacoustic processes under the nose fairing, taking into account the location of the sound-absorbing material.

Finite-Element Modeling of Filling Pressures in a Full-Scale Silo

2001 ◽  
Vol 127 (10) ◽  
pp. 1058-1066 ◽  
Author(s):  
J. F. Chen ◽  
S. K. Yu ◽  
J. Y. Ooi ◽  
J. M. Rotter
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Full Scale ◽  
Element Modeling
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