Techniques for Determining the Parameters of a Two-Dimensional Tire Model for the Study of Ride Comfort

1997 ◽  
Vol 25 (3) ◽  
pp. 187-213 ◽  
Author(s):  
F. Mancosu ◽  
G. Matrascia ◽  
F. Cheli

Abstract A rigid ring model of the tire for the study of in-plane dynamics and a new technique for determining the parameters of the model are presented in this paper. This model can be used for studying the comfort of vehicles, problems of driving, and braking problems in the longitudinal direction. Comparison with finite element models shows that the rigid ring model of the tire is capable of describing the in-plane eigenmode shapes in the frequency range of 0–130 Hz. The well-known “brush model,” integrated into the tire model, is introduced to take into account the slide phenomena in the contact patch. The parameters of the model can be correlated with the physical properties of the tire so that designers can take advantage of such a correlation in the development of new tires in terms of time, cost, and performance. The technique used to determine the parameters of the model for some automobile tires include the direct measurements of some physical properties (mass, moment of inertia, stiffness) and a method of identification applied on the results from a dynamic test. The model is able to predict experimental data in terms of natural frequencies and relative dampings. Results from the application of this technique on two tires are reported.

Author(s):  
Zeinab El-Sayegh ◽  
Moustafa El-Gindy ◽  
Inge Johansson ◽  
Fredrik Öijer

Abstract This paper focuses on predicting the out-of-plane rigid ring model parameters of an off-road truck tire running over a flooded surface. The truck tire size 315/80R22.5 used in this study is modeled using Finite Element Analysis (FEA) technique and validated in static and dynamic responses. The flooded surface is modeled using Smoothed-Particle Hydrodynamics (SPH) technique and Murnaghan equation of state. The contact between the truck tire and a flooded surface is defined using node-symmetric node-to segment contact with edge treatment algorithm. The out-of-plane rigid ring tire model parameters include the lateral stiffness, cornering stiffness, self-aligning moment stiffness, and relaxation length. The out-of-plane rigid ring model parameters are computed at different operating conditions including various inflation pressures, vertical loads and water depth. The effect of the previously mentioned operating conditions on the tire-flooded surface interaction is examined and investigated.


Author(s):  
Bin Li ◽  
Ning Li ◽  
Xiaobo Yang ◽  
James Yang

The tire is the main interface between the vehicle and road, and all maneuvers controlled by a driver to road vehicle are achieved by the interaction force between tire and road. In modern vehicle design, tire modeling plays an important role in effectively assessing vehicle handling, ride comfort, and road load analysis. The long term goal of this research is to develop a three-dimensional robust tire model that can be used for road load durability simulation. This work is the first step to the long term goal. This paper presents a new simplified in-plane tire model based on a traditional rigid ring tire model. The interaction between the tire and road is assumed to be patch contact. Optimization technique is used to obtain all key tire parameters of the tire model by minimizing the vertical and horizontal contact forces between the model simulation results and road test data when a tire passes a road bump. After the parameters are identified, a full factorial design of experiments with three levels for each of 8 parameters (horizontal spring stiffness and damper coefficient, vertical spring stiffness and damper coefficient, rotational spring stiffness and damper coefficient between the rim and ring, ring radius, ring residual spring stiffness) is conducted for parameter sensitivity analysis. The three levels for each parameter except the ring radius are 50% increase, 50% decrease, and nominal values. Sensitivity analysis has shown that several parameters are critical to the peak value of the vertical and horizontal contact forces. A quarter-car model is then used to assess ride comfort of the vehicle suspension system. The quarter-car model with the proposed tire model can more accurately predict the ride comfort subject to random road inputs than the one with point contact tire model.


2001 ◽  
Vol 29 (2) ◽  
pp. 108-132 ◽  
Author(s):  
A. Ghazi Zadeh ◽  
A. Fahim

Abstract The dynamics of a vehicle's tires is a major contributor to the vehicle stability, control, and performance. A better understanding of the handling performance and lateral stability of the vehicle can be achieved by an in-depth study of the transient behavior of the tire. In this article, the transient response of the tire to a steering angle input is examined and an analytical second order tire model is proposed. This model provides a means for a better understanding of the transient behavior of the tire. The proposed model is also applied to a vehicle model and its performance is compared with a first order tire model.


2008 ◽  
Vol 44-46 ◽  
pp. 871-878 ◽  
Author(s):  
Chu Yang Luo ◽  
Jun Jiang Xiong ◽  
R.A. Shenoi

This paper outlines a new technique to address the paucity of data in determining fatigue life and performance based on reliability concepts. Two new randomized models are presented for estimating the safe life and pS-N curve, by using the standard procedure for statistical analysis and dealing with small sample numbers of incomplete data. The confidence level formulations for the safe and p-S-N curve are also given. The concepts are then applied for the determination of the safe life and p-S-N curve. Two sets of fatigue tests for the safe life and p-S-N curve are conducted to validate the presented method, demonstrating the practical use of the proposed technique.


1998 ◽  
Vol 20 (3) ◽  
pp. 153-159
Author(s):  
J. Y. Lazennec ◽  
N. Mora Valladares ◽  
C. G. Laudet ◽  
D. Barabas ◽  
S. Ramare ◽  
...  

Author(s):  
Han Xu ◽  
Youqun Zhao ◽  
Qiuwei Wang ◽  
Fen Lin ◽  
Wei Pi

Mechanical elastic wheel (MEW) has the advantages of explosion-proof and prick-proof, which is conducive to the safety and maneuverability of the vehicle. However, the research on the performance of the full vehicle equipped with MEW is rare. Considering the particular properties of the radial and cornering stiffness of MEW, this paper aims to take into account both ride comfort and yaw stability of the vehicle equipped with the MEW through a nonlinear control method. Firstly, a 9-DOF nonlinear full vehicle model with the MEW tire model is constructed. The tire model is fitted based on experimental data, which corrects the impacts of vertical load on the cornering characteristic of the MEW. Then the full vehicle system is decoupled into four subsystems with a single input and a single output each according to active disturbance rejection control (ADRC) technology. In this process, the coupling relationship between different motions of the original system is regarded as the disturbance. Afterward, a novel nonlinear extended state observer is proposed, which has a similar structure of traditional linear extended state observer but smaller estimation error. Next, the control law of Backstepping-ADRC for different subsystems are derived respectively based on the Lyapunov theory. For the first time, the Backstepping-ADRC method is applied to the decoupling control of four-wheel steering and active suspension systems. Furthermore, the parameters of the controllers are adjusted through a multi-objective optimization scheme. Finally, simulation results validate the effectiveness and robustness of the proposed controller, especially when encountering some disturbances. The indices of vehicle body attitude and ride comfort are improved significantly, and also the yaw stability is guaranteed simultaneously.


2014 ◽  
Vol 6 ◽  
pp. 734568 ◽  
Author(s):  
Liang Tang ◽  
Jie Wu ◽  
Jinhao Liu ◽  
Cuicui Jiang ◽  
Wen-Bin Shangguan

Control Arm (CA) of a suspension plays an important role in the automotive ride comfort and handling stability. In this paper, the topology optimization model including ball joints and bushing for topology optimization of an aluminium CA is established, where a ball joint is simplified as rigid elements and the elastic properties of a rubber bushing are estimated using Mooney-Rivlin constitutive law. A method for treating with multiple loads in topology optimization of CA is presented. Inertia relief theory is employed in the FEA model of the CA in order to simulate the large displacement motion characteristics of the CA. A CA is designed based on the topology optimization results, and the strength, natural frequency, and rigidity of the optimized CA are calculated. The calculated results show that the performances of the optimized CA with the proposed model meet the predetermined requirements.


2018 ◽  
Vol 1145 ◽  
pp. 134-139
Author(s):  
Raghabendra Yadav ◽  
Bao Chun Chen ◽  
Hui Hui Yuan ◽  
Zhi Bin Lian

The dynamic testing of large-scale structures continues to play a significant role in earthquake engineering research. The pseudo- dynamic test (PDT) is an experimental technique for simulating the earthquake response of structures and structural components in time domain. A CFST-RC pier is a modified form of CFST laced column in which CFST members are connected with RC web in longitudinal direction and with steel tube in transverse direction. For this study, a CFST -RC pier is tested under three different earthquake time histories having scaled PGA of 0.05g. From the experiment acceleration, velocity, displacement and load time histories are observed. The dynamic magnification factors for acceleration due to Chamoli, Gorkha and Wenchuan ground motions are observed as 12, 10 and 10 respectively. The frequency of the pier is found to be 1.42 Hz. The result shows that this type of pier has excellent static and earthquake resistant properties.


2014 ◽  
Vol 31 (2) ◽  
pp. 326-345 ◽  
Author(s):  
Alexei Korolev ◽  
Alex Shashkov ◽  
Howard Barker

Abstract A new airborne instrument that measures extinction coefficient β in clouds and precipitation has been designed by Environment Canada. The cloud extinction probe (CEP) utilizes the transmissometric method, which is based on direct measurement of light attenuation between the transmitter and receiver. Transmissometers are known to be susceptible to forward scattering, which becomes increasingly significant as the particle size increases. A new technique for calibrating transmissometers was developed here in order to determine the response function of the probe. Laboratory calibrations show that CEP-derived β may be underestimated by a factor of 2 for circular particles with diameters greater than 100 μm. Results for spherical particles are in good agreement with theoretical predictions. For nonspherical particles, however, estimates of β can deviate significantly from those derived for spheres that have the same projected area. For in situ observations of ice particles, CEP measurements often deviate significantly from theoretical calculations, whereas for small cloud droplets agreement is good. It is hypothesized that CEP-derived estimates of β for ice clouds depend much on variations in the scattering phase function that arise from details in ice crystal surface roughness and fine crystal structure. This would complicate greatly the estimation of β from transmissometers for ice-bearing clouds.


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