ABSTRACT

The forces that enter the mounted tire spindle of laboratory-type tire dynamics test machines include the following items: (1) direct tire-generated forces, tire nonuniformities, and tread pattern vibrations; (2) direct tire-transmitted rough road surface or cleat impact forces; (3) direct machine resonance-amplified versions of items 1 and 2; (4) machine frame backpath-transmitted versions of items 1–3; (5) dynamic loadcell crosstalk; (6) external noise from foundation vibrations; and (7) adjacent load station vibrations traveling through the machine frame. Although items 1 and 2 are sought in spindle vibration measurements, items 3–7 are also included in the mix and confound the measurement, confusing the analyst into thinking that machine properties are tire properties. Not only do items 3–6 not exist in vehicle operation but also comparison of results from one test machine to another can be an exercise in comparing machine to machine, not tire to tire. Tire dynamics measurements should simulate tires in roadway operation, not create a whole new set of problems that do not exist in vehicles. Elimination of item 7 paved the way to developing a tire failure warning system that operates on tire endurance test machines and can be adapted for operation on passenger vehicles to warn the driver of tire trouble. This article develops the theory of stray force measurement, describes a method for eliminating stray forces from experimental tire dynamics data, and provides experimental verification of the effectiveness of these methods.

ABSTRACT

The main goal of this work is to investigate if finite element (FE) model techniques with special applications of material properties accurately estimate the parameters of flexible ring tire models. It is known that commercially available ring tire models are used as standard tools for simulating and predicting vehicle ride and durability, e.g., rigid ring MF-Swift [1] and flexible ring Flexible Structure Tire Model (FTire) [2–5]. Despite wide acceptance of these models, difficulty in model parameterization limits their application in the vehicle development process. For estimation of tire dynamic stiffnesses and inertial properties, rolling tire cleat test data are required for most ring models. Although this test method produces reliable models, the parameterization is not time and cost effective as it requires measurement and processing of cleat data at multiple speeds and loads and is prone to test rig dynamic compliance variations. This approach also limits the ability to evaluate tire performances during the virtual stages of tire design. The objective of this work is to develop virtual data using time and cost effective FE-based methods towards the estimation of flexible ring model parameters rather than relying on measured cleat data on physical tires. Commercial product ABAQUS is used for the FE simulations and FTire for tire flexible ring model simulations. Two FE modeling techniques are utilized in this work. Firstly, it is shown that the dynamic stiffness of a rolling tire can be estimated from a steady state eigensolution modal analysis of a static tire using material properties characterized for a rolling tire. Secondly, a method of separation of the sidewall from the tread band is developed for the estimation of mass and bending properties of the tread band. The estimated stiffnesses, inertias, and dimensions from the FE model results are converted into FTire model parameters. Finally, to validate the virtually generated FTire model, simulated dynamic cleat data response trends at multiple inflation pressures and velocities are compared with measurements. The virtual FE based techniques presented in this work can be applied to other ring based models as well.

ABSTRACT

While in nature, snow properties change from day to day or even minute by minute, one of the great advantages of lab tests is the stability and reproducibility of testing conditions. In our labs at the Institute of Dynamics and Vibration Research, Leibniz Universität Hannover, we currently run three test rigs that are able to conduct tests with tire tread blocks on snow and ice tracks: High-Speed Linear Tester (HiLiTe), Portable Friction Tester (PFT), and Reproducible Tread Block Mechanics in Lab (RepTiL). In the past years, we have run a project on the influence of snow track properties on friction and traction test results with those test rigs. In this article, we will present a first excerpt of the results concentrating on the RepTiL test rig. Because this rig reproduces the movement of rolling tire tread blocks, we executed a test campaign with special samples for the analysis of snow friction mechanics. We evaluated penetration into the snow, maximum longitudinal force level, and longitudinal force gradient. On the other hand, we varied the snow density while preparing our tracks to assess the influence of the snow track density on the friction mechanics. In parallel, we have accompanied our experiments with discrete element method simulations to better visualize and understand the physics behind the interaction between snow and samples. The simulation shows the distribution of induced stress within the snow tracks and resulting movement of snow particles. Hypotheses for the explanation of the friction behavior in the experiments were confirmed. Both tests and simulations showed, with good agreement, a strong influence of snow density and sample geometry.

acceleration decomposition

Application of Transient- and Steady-State Acceleration Signals in Intelligent Tires (T. Zhao, G. Liang, Y. Wang, and Y. Wei), 190-210 (2022)

accelerometer

Elimination of Stray Forces from Tire Dynamics Measurements or Beware the Backpath (G. R. Potts), 272-287 (2022)

adhesion friction

Prediction of Adhesion Friction Coefficient Using Two Different Models for Tire Tread Rubber Compounds (L. H. Espósito, E. S. Velasco, and A. J. Marzocca), 230-248 (2022)

ALE

Arbitrary Lagrangian-Eulerian Remeshing in FE Simulations of Tire Forming (I. Zreid, Y. Wei, and M. Kaliske), 370-376 (2022)

backpath

Elimination of Stray Forces from Tire Dynamics Measurements or Beware the

Comparison Between Tire Rolling Resistance Measurements on a Flat Track and a Test Drum Under Non-Steady-State Conditions

Lisa Ydrefors,

Mattias Hjort,

Sogol Kharrazi,

Jenny Jerrelind, and

Annika Stensson Trigell

Elimination of Stray Forces from Tire Dynamics Measurements or Beware the Backpath

ABSTRACT

Virtual Generation of Flexible Ring Tire Models Using Finite Element Analysis: Application to Dynamic Cleat Simulations

ABSTRACT

Investigation of the Influence of Snow Track Density on Tire Tread Block Traction by Experiments and Discrete Element Method Simulation

ABSTRACT

Theoretical Tire Model for Wear Progress of Tires with Tread Pattern Considering Two-Dimensional Contact Patch

ABSTRACT

Arbitrary Lagrangian-Eulerian Remeshing in FE Simulations of Tire Forming

ABSTRACT

Tire Science and Technology

Author Index to Volume 50 2022

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C

E

G

H

Tire Science and Technology

Keyword Index to Volume 50 2022

Comparison Between Tire Rolling Resistance Measurements on a Flat Track and a Test Drum Under Non-Steady-State Conditions

Critical Plane Analysis of Surface-Proximal Fields for the Simulation of Thermo-Mechanical Wear

Enhancing Tire Model Parameterization for Rollover Simulation: A Validated Approach

Research on Fast and Efficient Virtual Sample Delivery Method of Tire Mechanical Characteristics

Prediction of the Frictional Power Distribution in the Tire Contact Patch Based on an Empirical Tire Model and an Artificial Neural Network