Rail/wheel rolling noise generation due to parametric excitation

2020 ◽  
pp. 107754632096865
Author(s):  
Anders Nordborg
Keyword(s):  
Parametric Excitation ◽  
Iteration Scheme ◽  
Impulse Response Functions ◽  
Noise Generation ◽  
Noise Levels ◽  
Elastic Wheel ◽  
Wheel Rolling ◽  
Railway Rail ◽  
The Time Domain ◽  
Rolling Noise

When a wheel rolls over a railway rail, it ‘sees’ a varying stiffness downwards because the rail is periodically supported by sleepers, leading to parametric excitation of the rail/wheel system. This study investigates the importance of parametric excitation on railway noise generation. Because the problem is non-stationary, it is modelled in the time domain. Rail and wheel impulse response functions, together with an iteration scheme to match boundary conditions in the rail/wheel contact patch, yield rail and wheel response plus contact force at each wheel position on the rail. Forward velocity and rotation of the elastic wheel are accounted for. Feedback coupling between response and force takes part in the excitation. Numerical simulations show that, for a rail on stiff pads, parametric excitation is a major excitation mechanism, above all leading to increased excitation and noise levels in a broad frequency region around the pinned–pinned frequency.

Use of the kinematic radius in the rolling mechanics of an elastic wheel

2021 ◽  
pp. 17-27
Author(s):  
V.I. Kopotilov
Keyword(s):  
Traction Force ◽  
Rolling Resistance ◽  
Kinematic Parameter ◽  
Resistance Force ◽  
Elastic Wheel ◽  
Wheel Rolling ◽  
Physical Essence ◽  
Braking Force ◽  
Rolling Mode

The analysis of the physical essence of the kinematic and dynamic radii of the wheel is given. It is stated that the rolling radius of the wheel is a conditional kinematic parameter that characterizes only the rolling mode of the wheel. It is not the shoulder of all longitudinal forces acting on the wheel and should not be used to determine tractive forces, rolling resistance and wheel braking forces. Specific examples are given to illustrate the inappropriateness of using the kinematic radius to determine forces and moments. Keywords: elastic wheel, rolling radius, kinematic radius, dynamic radius, arm of force, traction force, rolling resistance force, braking force, rolling mode

scholarly journals Analytical determination of application point and normal reaction arm when rolling a wheel on a drum

2021 ◽  
Vol 341 ◽  
pp. 00039
Author(s):  
Maria Karelina ◽  
Tatyana Balabina ◽  
Alexey Mamaev
Keyword(s):  
Rolling Resistance ◽  
Analytical Determination ◽  
Support Surface ◽  
Rigid Support ◽  
Normal Reaction ◽  
Normal Forces ◽  
Elastic Wheel ◽  
Wheel Rolling ◽  
Force Equilibrium

Evaluation of the rolling resistance of car tires is now often performed on drum stands like car tests. This necessitates the study of the mechanics of interaction between the wheel and the drum in order to determine its force and kinematic characteristics, including the values and points of application of tangential and normal forces in contact with the drum. These problems can be solved taking into account that the mechanics of elastic wheel rolling on a drum is the same as when rolling on a flat rigid support surface. In this paper, from consideration of the mechanics of interaction between an elastic wheel and a drum, using the equations of power balance and force equilibrium of the wheel, the equations for determining the point of normal reaction in contact and its arm relative to the wheel axis during its rolling along one and two drums have been derived.. These dependencies have a simple form and can be applied when considering the rolling of both a single wheel and the car as a whole on a drum stand.

Vibrations and Waterborne Noise on Fishery Vessels

1988 ◽  
Vol 32 (02) ◽  
pp. 112-133
Author(s):  
W. Ojak
Keyword(s):  
United Nations ◽  
Noise Generation ◽  
Noise Levels ◽  
Structural Vibrations ◽  
Mechanical Vibrations ◽  
Noise Propagation ◽  
Research Institutes ◽  
Fishery Research ◽  
Elastically Supported ◽  
Agricultural Organization

The Food and Agricultural Organization of the United Nations granted a fellowship to the author to study, at several European ship research institutes, the problem of noise generation and propagation on fishery vessels. He later took part in the design of the fishery research vessel Prof. Siedlecki, which included the implementation of a series of antivibration and antinoise precautions. This paper compares vibration and noise levels on two fishery research vessels—the conventional RV G.O.Sars and RV Prof. Siedlecki. The paper is divided into two parts. In the first part, mechanical vibrations of the elastically supported propeller are dealt with and conditions for minimum vibration response are determined. In the second part, structural vibrations in the ships and noise propagation from the ships to the water are described. The paper concludes with data on structural vibrations and waterborne noise propagation. This paper, and the paper published in the June 1984 issue of JOURNAL OF SHIP RESEARCH [1],2 completes the author's approach to propeller vibrations.

On the Modelling of Noise Generation in Corrugated Pipes

2009 ◽  
Author(s):  
Hugh Goyder
Keyword(s):  
Vortex Shedding ◽  
Oil And Gas ◽  
Natural Frequencies ◽  
Oil And Gas Industry ◽  
Noise Generation ◽  
Noise Levels ◽  
Eigenvalue Approach ◽  
Gas Industry ◽  
Offshore Oil And Gas ◽  
Offshore Oil

The offshore oil and gas industry uses pipes which are made flexible by means of a corrugated construction. Those pipes that run from a platform to the seabed are known as risers while those that connect two pipes on the seabed are known as jumpers. Gas flowing within the pipe interacts with the corrugations and generates noise. This noise is of concern because it is of sufficient amplitude to cause pipework vibration with the threat of fatigue and pipe breakages. This paper examines the conditions that give rise to the large noise levels. The conditions for the onset of noise are investigated using an eigenvalue approach which involves the effect of damping due to losses from the pipe boundaries and pipe friction. The investigation which is conducted in terms of reflection conditions shows why only few of the very many possible natural frequencies are selected. The conditions for maximum noise response are also investigated using a non-linear model of vortex shedding. Here an approach is developed in which the net power generated along a single wavelength is calculated.

scholarly journals Transient Response of an Impacted Beam and Indirect Impact Force Identification Using Strain Measurements

1994 ◽  
Vol 1 (3) ◽  
pp. 267-278 ◽  
Author(s):  
Hyungsoon Park ◽  
Youn-sik Park
Keyword(s):  
Impulse Response ◽  
Impact Force ◽  
Impulse Response Function ◽  
Time History ◽  
Impulse Response Functions ◽  
Transverse Impact ◽  
History Of ◽  
Convolution Approach ◽  
The Time Domain ◽  
The Impact

The impulse response functions (force-strain relations) for Euler–Bernoulli and Timoshenko beams are considered. The response of a beam to a transverse impact force, including reflection at the boundary, is obtained with the convolution approach using the impulse response function obtained by a Laplace transform and a numerical scheme. Using this relation, the impact force history is determined in the time domain and results are compared with those of Hertz's contact law. In the case of an arbitrary impact, the location of the impact force and the time history of the impact force can be found. In order to verify the proposed algorithm, measurements were taken using an impact hammer and a drop test of a steel ball. These results are compared with simulated ones.

On the Modelling of Noise Generation in Corrugated Pipes

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Hugh Goyder
Keyword(s):  
Vortex Shedding ◽  
Oil And Gas ◽  
Natural Frequencies ◽  
Oil And Gas Industry ◽  
Noise Generation ◽  
Noise Levels ◽  
Eigenvalue Approach ◽  
Gas Industry ◽  
Offshore Oil And Gas ◽  
Offshore Oil

The offshore oil and gas industry uses corrugated pipes because of their flexibility. Gas flowing within these pipes interacts with the corrugations and generates noise. This noise is of concern because it is of sufficient amplitude to cause pipework vibration with the threat of fatigue and pipe breakages. This paper examines the conditions that give rise to the large noise levels. These conditions, for the occurrence of noise, are investigated using an eigenvalue approach, which involves the effect of damping due to losses from the pipe boundaries and pipe friction. The investigation is conducted in terms of reflection conditions and shows why only few of the very many possible natural frequencies are selected. The conditions for maximum noise response are also investigated by means of a nonlinear model of vortex shedding. Here, an approach is developed in which the net power generated by each wavelength is calculated.

Nonlinear Effects of Wave Heights on Coupled Sloshing and Seakeeping Responses

2018 ◽  
Author(s):  
Xin Wang ◽  
Makoto Arai ◽  
Gustavo Karuka
Keyword(s):  
Natural Gas ◽  
Numerical Method ◽  
Three Dimensional ◽  
Nonlinear Effects ◽  
Numerical Code ◽  
Ship Motions ◽  
Impulse Response Functions ◽  
Weakly Nonlinear ◽  
Wave Heights ◽  
The Time Domain

With increased activities in natural gas transportation and offshore exploration in the past decades, assessment of sloshing in liquefied natural gas (LNG) tanks has become an important practical issue. In this paper, we focus on the deterministic calculation of the coupled sloshing and ship motions in regular wave conditions. An in-house numerical code is used to solve the seakeeping problem coupled with the sloshing dynamics. The numerical method adopts a weakly nonlinear approach using impulse response functions for the seakeeping problem. Nonlinear Froude-Krylov and hydrostatic forces are directly evaluated in the time domain. A three-dimensional finite difference method is applied to solve the sloshing problem. The numerical method is validated by comparing with experimental results in the literature. The developed numerical method is used to analyze the nonlinear effects of wave heights.

Using the kinematic radius in the mechanics of elastic wheel rolling

2021 ◽  
pp. 13-22
Author(s):  
V.I. Kopotilov
Keyword(s):  
Traction Force ◽  
Rolling Resistance ◽  
Clear Understanding ◽  
Elastic Wheel ◽  
Wheel Rolling ◽  
Instantaneous Center ◽  
Wheeled Vehicles

As you know, in the mechanics of a wheel with an elastic tire, both dynamic (rd) and kinematic (rk) radius are widely used. At the same time, specialists in the theory of the motion of wheeled vehicles still do not have a clear understanding of the scope of their application. Keywords: elastic wheel, kinematic radius, circumferential force, dynamic radius, wheel traction force, instantaneous center of speeds, torque, solid, rolling resistance

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