A New Tire Model to Predict Vibration Emission of Counterbalance Trucks

2000 ◽  
Vol 28 (2) ◽  
pp. 119-137 ◽  
Author(s):  
P. Lemerle ◽  
P. Mistrot
Keyword(s):  
Numerical Model ◽  
Numerical Simulations ◽  
Close Agreement ◽  
Industrial Sector ◽  
Tire Model ◽  
Suspension Systems ◽  
Truck Tires ◽  
Pneumatic Tires

Abstract Counterbalance trucks are machines in widespread use in every industrial sector. Unlike cars, they are not designed with suspension systems. Consequently, they are considered to be high vibrating vehicles. Nevertheless, like suspension seats, tires can be selected as suspension parts. This paper presents a new numerical model for the analysis of the vibratory behavior of counterbalance truck tires. This model was intended to be a part of a fork lift truck model, including axles, chassis, and cabin. All the results reported here show a close agreement between measurements and numerical simulations. Thus, it can predict the vibration emission values at the driving position and is used to compare the efficiency of solid tires with pneumatic tires in terms of transmitted vibration levels.

Tread Depth Effects on Tire Rolling Resistance

2001 ◽  
Vol 29 (3) ◽  
pp. 134-154 ◽  
Author(s):  
J. R. Luchini ◽  
M. M. Motil ◽  
W. V. Mars
Keyword(s):  
Finite Element Analysis ◽  
Common Knowledge ◽  
Rolling Resistance ◽  
Test Method ◽  
Tire Model ◽  
Element Analysis ◽  
Truck Tires ◽  
The Finite Element Analysis ◽  
Equilibrium Test ◽  
Depth Effects

Abstract This paper discusses the measurement and modeling of tire rolling resistance for a group of radial medium truck tires. The tires were subjected to tread depth modifications by “buffing” the tread surface. The experimental work used the equilibrium test method of SAE J-1269. The finite element analysis (FEA) tire model for tire rolling resistance has been previously presented. The results of the testing showed changes in rolling resistance as a function of tread depth that were inconsistent between tires. Several observations were also inconsistent with published information and common knowledge. Several mechanisms were proposed to explain the results. Additional experiments and models were used to evaluate the mechanisms. Mechanisms that were examined included tire age, surface texture, and tire shape. An explanation based on buffed tread radius, and the resulting changes in footprint stresses, is proposed that explains the observed experimental changes in rolling resistance with tread depth.

scholarly journals Wind shear over the Nice Côte d'Azur airport: case studies

2013 ◽  
Vol 13 (9) ◽  
pp. 2223-2238 ◽  
Author(s):  
A. Boilley ◽  
J.-F. Mahfouf
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Numerical Simulations ◽  
Wind Shear ◽  
Horizontal Wind ◽  
Wind Profiler ◽  
Measurement Campaign ◽  
Wind Lidar ◽  
Real Time Applications ◽  
Wind Shears

Abstract. The Nice Côte d'Azur international airport is subject to horizontal low-level wind shears. Detecting and predicting these hazards is a major concern for aircraft security. A measurement campaign took place over the Nice airport in 2009 including 4 anemometers, 1 wind lidar and 1 wind profiler. Two wind shear events were observed during this measurement campaign. Numerical simulations were carried out with Meso-NH in a configuration compatible with near-real time applications to determine the ability of the numerical model to predict these events and to study the meteorological situations generating an horizontal wind shear. A comparison between numerical simulation and the observation dataset is conducted in this paper.

Multifidelity Recursive Cokriging for Dynamic Systems' Response Modification

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Luigi Bregant ◽  
Lucia Parussini ◽  
Valentino Pediroda
Keyword(s):  
Numerical Model ◽  
Numerical Simulations ◽  
Dynamic Systems ◽  
System Optimization ◽  
The Other ◽  
Experimental Measurements ◽  
Reciprocal Influence ◽  
Tests And Measurements ◽  
Invaluable Tool ◽  
Mixed Approach

In order to perform the accurate tuning of a machine and improve its performance to the requested tasks, the knowledge of the reciprocal influence among the system's parameters is of paramount importance to achieve the sought result with minimum effort and time. Numerical simulations are an invaluable tool to carry out the system optimization, but modeling limitations restrict the capabilities of this approach. On the other side, real tests and measurements are lengthy, expensive, and not always feasible. This is the reason why a mixed approach is presented in this work. The combination, through recursive cokriging, of low-fidelity, yet extensive, numerical model results, together with a limited number of highly accurate experimental measurements, allows to understand the dynamics of the machine in an extended and accurate way. The results of a controllable experiment are presented and the advantages and drawbacks of the proposed approach are also discussed.

scholarly journals Construction of a numerical model of suspension in a numerical simulation of sedimentation

2018 ◽  
Vol 46 ◽  
pp. 00011
Author(s):  
Krzysztof Kołodziejczyk
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Numerical Simulations ◽  
Particle Composition ◽  
Polydisperse Particle ◽  
Multiphase Systems ◽  
The Moment ◽  
Definition Of ◽  
Selection Of ◽  
The Way

Modeling of multiphase systems, which includes suspensions, is an issue that is continually developed. There are no procedures at the moment that would clearly determine the way in which suspension is defined in numerical simulations. The article presents an analysis of the selection of a numerical model and the definition of the suspension with a polydisperse particle composition.

scholarly journals Collisional Ring Galaxies in Small Groups

2000 ◽  
Vol 174 ◽  
pp. 277-280
Author(s):  
C. Horellou
Keyword(s):  
High Resolution ◽  
Numerical Model ◽  
Numerical Simulations ◽  
Small Groups ◽  
Large Scale ◽  
Rotating Disk ◽  
Groups Of Galaxies ◽  
Ring Galaxies ◽  
History Of

AbstractThe probability of plunging orbits is enhanced in groups of galaxies and indeed, observations show that ring galaxies, which are believed to form when a galaxy passes through the center of a larger rotating disk, are often found in small groups. Numerical simulations combined with a knowledge of the large-scale H I distribution provide strong constraints on the dynamical history of these systems and on the identity of the intruder. Here we present a numerical model of the Cartwheel galaxy which supports the suggestion that the most distant companion is the intruder. We also present high-resolution H I observations of the more irregular system Arp 119 that reveal a possible connection to the most distant companion.

Experimental Observations and Numerical Simulations of Wave Impact Forces on Recurved Parapets Mounted Above a Vertical Wall

2009 ◽  
Author(s):  
David Newborn ◽  
Nels Sultan ◽  
Pierre Beynet ◽  
Tim Maddux ◽  
Sungwon Shin ◽  
...  
Keyword(s):  
Numerical Model ◽  
Numerical Simulations ◽  
Shear Force ◽  
Experimental Testing ◽  
Vertical Wall ◽  
Experimental Tests ◽  
Vertical Force ◽  
Base Shear ◽  
Wave Impact ◽  
Overturning Moment

Large-scale hydraulic model tests and detail numerical model investigations were conducted on recurved wave deflecting structures to aid in the design of wave overtopping mitigation for vertical walls in shallow water. The incident wave and storm surge conditions were characteristic return period events for an offshore island on the North Slope of Alaska. During large storm events, despite depth-limited wave heights, a proposed vertical wall extension was susceptible to wave overtopping, which could potentially cause damage to equipment. Numeric calculations were conducted prior to the experimental tests and were used to establish the relative effectiveness of several recurved parapet concepts. The numerical simulations utilized the COrnell BReaking waves and Structures (COBRAS) fluid modeling program, which is a Volume-of-Fluid (VOF) model based on Reynolds Averaged Navier-Stokes equations [1] [2]. The experimental testing was conducted in the Large Wave Flume (LWF) at Oregon State University, O.H. Hinsdale Wave Research Laboratory. The experimental test directly measured the base shear force, vertical force, and overturning moment applied to the recurved parapets due to wave forcing. Wave impact pressure on the parapet and water particle velocities seaward of the wall were also measured. Results from the experimental testing include probability of exceedance curves for the base shear force, vertical force, and overturning moment for each storm condition. Qualitative comparisons between the experimental tests and the COBRAS simulations show that the numerical model provides realistic flow on and over the parapet.

scholarly journals Numerical Simulations of Clay Tiles Compression

2012 ◽  
Vol 504-506 ◽  
pp. 1403-1408 ◽  
Author(s):  
Jérémie Vignes ◽  
Fabrice Schmidt ◽  
Gilles Dusserre ◽  
Olivier de Almeida ◽  
Jean Frédéric Dalmasso
Keyword(s):  
Numerical Model ◽  
Tensile Stress ◽  
Numerical Simulations ◽  
Compression Tests ◽  
Rheological Study ◽  
Constitutive Parameters ◽  
Actual Geometry ◽  
Clay Tiles ◽  
Force Displacement ◽  
Tribological Parameters

During the pressing step, the clay tiles undergo stresses which result in the appearance of defects. A rheological study, based on free compression tests, allowed to confirm the Elasto-visco-plastic behaviour of the clay. The different constitutive parameters were estimated by fitting the force-displacement experimental curves using the optimisation algorithm (ES Metamodel) implanted in the commercial software Forge 2009®. The influence of the tribological parameters was studied using squeezing numerical simulations of a full tile. The numerical model was validated with experimental squeezing test of technological specimen with a tile lug. Then, we have compared experimental force with the numerical one and deduced that the clay/tool interface is not perfectly sliding. A friction Tresca’s law was used to model the clay/tool interface. Numerical results showed that the actual geometry of tile lug didn’t allow to form correctly the tile. Several areas undergo tensile stress, air traps ,... A new geometry of tile lug was proposed in order to limit this phenomenon. Using a simplified defect criteria (Latham and Cockroft), the numerical model allowed to locate the areas where there is a risk of crack.

An Experimental Demonstrator of Semi-Active Tire Damping Enhancement

2015 ◽  
Author(s):  
Vladimir V. Vantsevich ◽  
Gabriel D. Judd
Keyword(s):  
Vibration Control ◽  
Damping Ratio ◽  
Rolling Resistance ◽  
Analysis Procedure ◽  
Power Losses ◽  
External Excitation ◽  
Pneumatic Tire ◽  
Suspension Systems ◽  
Pneumatic Tires

Pneumatic tires play a greater role in vibration control of vehicles with stiff or no suspension systems. The challenge is to find an approach that enhances vibratory damping in the tires without increasing the power losses due to rolling resistance effects. This paper presents a novel tire damping enhancement that allows for improved damping within the tire while maintaining the rolling resistance found in a typical pneumatic tire. The damping enhancement was evaluated by testing an apparatus/demonstrator that simulates a pneumatic tire. The experiment was initially configured to measure the damping ratio of the conventional tire design using a calibrated external excitation and analyzing the decay of the vibration. The damping enhancement presented in the paper was then subjected to the same test and analysis procedure. Results of the analysis show that the proposed damping enhancement measurably decreased the time of the vibratory oscillation.

Numerical Modeling of the Phenomena of Frictional Coupling between Wheel and Rail to Describe and Verify the Operation of Surface Condition Detector

2015 ◽  
Vol 220-221 ◽  
pp. 251-256 ◽  
Author(s):  
Andrzej Niedworok ◽  
Andrzej Baier
Keyword(s):  
Numerical Modeling ◽  
Friction Coefficient ◽  
Numerical Model ◽  
Numerical Simulations ◽  
Surface Condition ◽  
Measuring Transducer ◽  
Rail Vehicles ◽  
Testing Facility ◽  
Braking Torque ◽  
Braking Distance

Presentation of the numerical model describing a design and functionality of the prototype of surface condition detector is the paper subject. The detector, by monitoring the frictional coupling between so-called “tracking wheel” of the dedicated measuring transducer and a rail can analyse the condition of rail surface (presence of any factor that can deteriorate friction coefficient) [1]. Signal generated at the detector outlet, carrying information about local condition of rail surface, can be used to adjust braking torque of vehicles or machines moving on a track. Authors expect that implementation of the method will eliminated dangerous elongation of braking distance of rail vehicles in the result of loss of adhesion. Structure of detector of rail surface condition is described and its principle of operation is presented in a form of numerical model. Results of numerical simulations are given and they are compared with the measurements taken on the testing facility in real conditions.

Radial-Interradial Spring Tire Models

1988 ◽  
Vol 110 (1) ◽  
pp. 70-75 ◽  
Author(s):  
J. M. Badalamenti ◽  
G. R. Doyle
Keyword(s):  
Test Data ◽  
Close Agreement ◽  
Tire Model ◽  
Drag Forces ◽  
Tire Models

Two radial-interradial spring tire models are developed to predict vertical and drag forces produced by a tire as it rolls over an obstacle. Interradial springs are used to interconnect radial linear or quadratic springs to make each tire element’s deflection dependent upon its adjacent element’s deflections. Forces predicted by these two models are compared with a previously developed quadratic radial spring tire model and test data. The newly developed quadratic radial-linear interradial spring tire model predicts vertical and drag forces that are in close agreement with the test data.

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