Validation of a finite element model for axle box acceleration at squats in the high frequency range

2014 ◽  
Vol 141 ◽  
pp. 84-93 ◽  
Author(s):  
Maria Molodova ◽  
Zili Li ◽  
Alfredo Núñez ◽  
Rolf Dollevoet
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
High Frequency ◽  
Element Model ◽  
High Frequency Range ◽  
Frequency Range

Smoothed Finite Element Methods for Predicting the Mid to High Frequency Acoustic Response in the Cylinder-Head Chamber of a Diesel Engine

2019 ◽  
Vol 17 (09) ◽  
pp. 1950060
Author(s):  
Tengfei Dai ◽  
Xia Jin ◽  
Huaze Yang ◽  
Tianran Lin ◽  
Yuantong Gu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Diesel Engine ◽  
Modeling And Simulation ◽  
Finite Element Methods ◽  
High Frequency ◽  
Cylinder Head ◽  
High Frequency Range ◽  
Acoustic Response ◽  
Frequency Range

Modeling and simulation of the acoustic response in enclosed cavities of a diesel engine are of great significance for optimal design of an engine to achieve a better acoustic performance. Nevertheless, the use of the traditional finite element method (FEM) for the mid to high frequency acoustic prediction is limited by the well-known numerical dispersion errors and the tedious preprocessing of the model. Smoothed finite element methods (SFEMs) proposed originally for solid mechanics have been employed for the modeling of acoustic problems in the low to medium frequency ranges whilst acoustic modeling in the mid to high frequency range remains untouched. This paper comprehensively investigates into the performance of SFEMs in modeling and simulation of mid to high frequency acoustic problems. It is shown that the mass-redistributed edge-based smoothed finite element method (MR-ES-FEM) can yield an excellent prediction result in the mid to high frequency range in terms of accuracy, efficiency and robustness. The MR-ES-FEM is also used to simulate sound propagation in a cylinder head chamber of a four-cylinder diesel engine to prove its effectiveness. The findings presented in this paper offer an in-depth insight for engineers to select suitable numerical methods for solving mid to high frequency acoustic problems in the design of diesel engines.

Effects of tip relief on vibration responses of a geared rotor system

2013 ◽  
Vol 228 (7) ◽  
pp. 1132-1154 ◽  
Author(s):  
Hui Ma ◽  
Jian Yang ◽  
Rongze Song ◽  
Suyan Zhang ◽  
Bangchun Wen
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Spur Gear ◽  
Rotor System ◽  
Time Varying ◽  
Frequency Range ◽  
Mesh Stiffness ◽  
Resonance Frequencies ◽  
Vibration Responses

Considering tip relief, a finite element model of a spur gear pair in mesh is established by ANSYS software. Time-varying mesh stiffness under different amounts of tip relief is calculated based on the finite element model. Then, a finite element model of a geared rotor system is developed by MATLAB software considering the effects of time-varying mesh stiffness and constant load torque. Emphasis is given to the effects of tip relief on the lateral–torsional coupling vibration responses of the system. The results show that as the amount of tip relief increases, the saltation of time-varying mesh stiffness reduces at the position of approach action and transition mesh region from the single tooth to double tooth. A number of primary resonances and some super-harmonic of gears 1 and 2 are excited by time-varying mesh stiffness in amplitude frequency responses. As the amount of tip relief increases, some super-harmonic responses change due to the variation in the higher frequency components of time-varying mesh stiffness. After tip relief, the vibration and meshing force decrease obviously at lower mesh frequency range except at some resonance frequencies; however, tip relief is not effective in reducing the vibration at higher mesh frequency range. The amplitude fluctuation of the vibration acceleration reduces evidently after considering tip relief, which is not remarkable with the increase of meshing frequency.

Extended Solution of a Trimmed Vehicle Finite Element Model in the Mid-Frequency Range

2020 ◽  
Author(s):  
David Sipos ◽  
Markus Brandstetter ◽  
Antoine Guellec ◽  
Jonathan Jacqmot ◽  
Daniel Feszty
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Frequency Range

The use of microperforated materials as duct liners: Comparison with fibrous linings

2020 ◽  
Vol 68 (4) ◽  
pp. 269-282
Author(s):  
Hyunjun Shin ◽  
J. Stuart Bolton
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
High Performance ◽  
Analytical Data ◽  
Element Model ◽  
Fibrous Materials ◽  
Frequency Range ◽  
Mental Work ◽  
Alternative Approach ◽  
Limited Frequency

The acoustical performance of a microperforated duct liner and a fibrous lining was compared to confirm that a microperforated panel lining can be used to re- place a fibrous liner as a sound attenuator in a duct. Fibrous materials are often used to line ducts in order to attenuate HVAC noise, for example. These treatments are often primarily useful in a limited frequency range owing to the characteristics of non-planar wave propagation in ducts. At the same time, microperforated mate- rials backed by a finite-depth air space are effective in a limited frequency range owing to the nature of the reactive impedance of this combination. Here, it will be shown that microperforated materials may be used to create duct linings that produce attenuation comparable with that of fibrous materials in the latter's high- performance region. The characteristics of the microperforated panel were studied based on the Maa model. To compare the performance of these two linings, theoret- ical, numerical and experimental tools were used. In the various case studies, both extended reaction and locally reacting treatments were considered. For the analyti- cal approach, Morse's theory was applied in the local reaction case. On the other hand, Scott's analysis was used to study the extended reaction case. In the experi- mental work, the transmission losses of various liner configurations were measured in a square impedance tube. To tune the performance of a microperforated sheet to reproduce that of a fibrous material, the hole size, porosity, thickness, density, and air-backing depth were modified. To validate the experimental and analytical data and to handle situations that are not easily modeled using an analytical approach, a finite element model was also used for the calculations. For the finite element model analysis, COMET/VISION and SAFE were used. Since that software does not include explicit microperforated material models, an alternative approach was used. The alternative model was based on the Attala and Sgard model for perforated panels. This alternative approach in which the perforated panel is modeled as a thin porous layer was successfully implemented in finite element form. Finally, it was demonstrated that the microperforated panel can successfully reproduce the acous- tical performance of glass fiber as a duct lining material.

scholarly journals Micro-perforated panels for noise reduction

2021 ◽  
Author(s):  
Sebastian Floss ◽  
Felix Czwielong ◽  
Stefan Becker ◽  
Manfred Kaltenbacher
Keyword(s):  
Finite Element ◽  
High Frequency ◽  
Room Acoustics ◽  
High Frequency Range ◽  
Duct Flow ◽  
Frequency Range ◽  
Fan Performance ◽  
Safety Regulations ◽  
Axial Fans ◽  
Cavity Configuration

AbstractSpace limitations in duct applications, new industrial and health safety regulations require new absorber configurations. Micro-perforated panels (MPP) as used in micro-perforated absorbers (MPA) allow new sound absorber concepts in the category of metamaterials. In this contribution we investigate MPA designs for the low and mid-to-high frequency range and apply finite element (FE) simulations to precisely design absorber configurations for applications in room acoustics and axial fans. The investigations show that the MPA’s cavity configuration must be customized for the desired frequency range and has significant influence on fan performance when applied in a duct flow setup.

Damping Control in a Sandwich Structure With SMP Core

2015 ◽  
Author(s):  
Pauline Butaud ◽  
Morvan Ouisse ◽  
Emmanuel Foltête
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Sandwich Structure ◽  
Damping Ratio ◽  
Shape Memory Polymer ◽  
Viscoelastic Model ◽  
Element Model ◽  
Numerical Approach ◽  
Wide Frequency Range ◽  
Frequency Range

A shape memory polymer (SMP), the tBA/PEGDMA, is elaborated and characterized. The dynamic mechanical characterization of this SMP highlights promising damping properties. The frequency and temperature dependency of the SMP is represented by a viscoelastic model allowing the introduction of the material in the design process of complex structures. A composite sandwich is developed by coupling the SMP with aluminum skins. A finite element model is developed for modeling the behavior of the SMP when integrated in a sandwich structure. The damping performances obtained by the numerical approach are validated experimentally using modal analysis. The experimental results are found to be in good agreement with the predictions of the finite element model. Furthermore, it is found that the controlled heating of the SMP core allows damping the structure over a wide frequency range. The SMP core temperature is tuned from the time-temperature superposition through a calibration curve to correspond to optimal values of damping ratio in the frequency range of interest; a vibration attenuation of about 20dB is observed.

Vehicle-Track Dynamic Simulations of a Locomotive Considering Wheelset Structural Flexibility and Comparison with Measurements

2005 ◽  
Vol 219 (4) ◽  
pp. 225-238 ◽  
Author(s):  
N Chaar ◽  
M Berg
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Elastic Deformation ◽  
Element Model ◽  
Dynamic Interaction ◽  
Structural Flexibility ◽  
Frequency Range ◽  
Dynamic Simulations ◽  
Present Context ◽  
Parametric Studies

Wheelset structural flexibility, that is the elastic deformation of the wheelset as a structure, can significantly influence the vehicle-track dynamic interaction. In this paper on-track simulations considering flexible wheelsets, modelled through eigenmodes derived from a finite element model, are presented and compared with on-track measurements. The effects of the wheelset structural flexibility on track forces, in the frequency range 0-100 Hz, are investigated. Results from parametric studies are also presented. The present application is a Swedish Rc7 locomotive having rather slender wheelsets. It is shown that both lateral and vertical track forces are significantly influenced by the wheelset flexibility and that the agreement with measurements is fairly good. The wheelset flexibility increases the lateral track forces. The track representation in the present context is important and the used so-called moving track model needs improvements.

scholarly journals Mathematical and laboratory modeling of resonant impact on the spike for the purpose of grain selection

2020 ◽  
Vol 210 ◽  
pp. 05017
Author(s):  
Arkady Soloviev ◽  
Andrey Matrosov ◽  
Ivan Panfilov ◽  
Besarion Meskhi ◽  
Oleg Polushkin ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Resonance Frequency ◽  
High Frequency ◽  
Low Frequency ◽  
Element Model ◽  
Laboratory Modeling ◽  
Full Scale Experiment ◽  
High Frequency Vibrations ◽  
Scale Experiment

Mathematical and computer finite element model in the ACELAN package of resonant impact on a spike was developed and a full-scale experiment was carried out. Two installations are considered, one based on a cantilever, the free end of which acts on the spike, and the second is a semi-passive round bimorph. Excitation of vibrations is carried out using an actuator based on piezoceramic elements. In the first installation, low-frequency vibrations of the stem with a spike are excited and the resonance frequency is determined at which only an spike with grain performs intense vibrations. The second installation is designed to excite high-frequency vibrations at which resonant movements of the grains themselves arise. The purpose of both installations is to separate the grain from the spike using resonance phenomena.

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