Bias Truck Tire Deformation Analysis with Finite Element Modeling

This paper presents a method for modeling of pneumatic bias tire axisymmetric deformation. A previously developed model of all-steel radial tire was expanded to include the non-linear stress–strain relationship for textile cord and its thermal shrinkage. Variable cord density and cord angle in the cord-rubber bias tire composite are the major challenges in pneumatic tire modeling. The variabilities result from the tire formation process, and they were taken into account in the model. Mechanical properties of the composite were described using a technique of orthotropic reinforcement overlaying onto isotropic rubber elements, treated as a hyperelastic incompressible material. Due to large displacements, the non-linear problem was solved using total Lagrangian formulation. The model uses MSC.Marc code with implemented user subroutines, allowing for the description of the tire specific properties. The efficiency of the model was verified in the simulation of mounting and inflation of an actual bias truck tire. The shrinkage negligence effect on cord forces and on displacements was examined. A method of investigating the influence of variation of cord angle in green body plies on tire apparent lateral stiffness was proposed. The created model is stabile, ensuring convergent solutions even with large deformations. Inflated tire sizes predicted by the model are consistent with the actual tire sizes. The distinguishing feature of the developed model from other ones is the exact determination of the cord angles in a vulcanized tire and the possibility of simulation with the tire mounting on the rim and with cord thermal shrinkage taken into account. The model may be an effective tool in bias tire design.

TRT EVO: Advances in real-time thermodynamic tire modeling for vehicle dynamics simulations

Vehicle performances, especially in motorsport, are deeply affected by tire behavior and in particular by tire compound proper working conditions. In this research activity, a series of innovations have been introduced on the Thermo Racing Tire (a physical-analytical tire thermal model, based on Fourier’s law of heat transfer applied to a three-dimensional domain) in order to take into account all the main aspects actively involved in the thermal behavior of the tire, as the presence of exhausted gases eventually impacting at the rear axle and the inhomogeneous distribution of local variables (pressure, stress and sliding velocity) within the contact patch, caused in example by the tire camber angle. The new model developed considers the presence of the sidewalls, actively involved in the convective heat exchanges, respectively, with the external airflow and the inner gas fluid, located inside the inflation chamber. The aim of the new version of the tire thermal model is a better physical comprehension of all the phenomena concerning the contact with the asphalt and the prediction of the link between the thermal state and the frictional performance, crucial for the definition of an optimal wheel and vehicle setup.

Kinematics and Dynamics Analysis of McPherson Suspension Based on Planar 1/4 Vehicle Model

The nonlinear asymmetric problem of McPherson suspension has become a challenging problem in the process ofestablishing the system model. This paper presents a planar 1/4-vehicle model that not only takes into account thevertical vibration of the sprung mass (chassis), but also includes: ix spring mass (wheel assembly) sliding and rotation;ii longitudinal wheel mass And its moment of inertia; iii tire damping and lateral defl ection. This dynamic kinematicmodel provides a solution to two important shortcomings of the traditional 1/4 vehicle model: it explains geometricmodeling and tire modeling. This paper provides a systematic development of the planar model and a completemathematical equation. This analysis model can be applied to hardware in the rapid calculation of ring applications. Inaddition, the model also gives a repeatable Simulink simulation implementation. The model has been compared withthe actual Adams / View simulation to analyze the vibration and rebound motion of the wheel, as well as two relatedmotion parameters: the dynamic characteristics of the camber and the pitch change.

A Novel Parameter Identification Method for Tire Models

A novel parameter identification method for dynamics models of pneumatic tire was presented. The parameter identification process and methodology relate to Nelder-Mead algorithm, genetic algorithm and random value method. Based on experimental data and tire modeling of PAC2002, the lateral force parameters, longitudinal force parameters and aligning moment parameters were identified by using the presented identification approach. It can be found that the novel parameter identification approach is more accurate and efficient, which can provide theoretic evidence for tire modeling and analysis. Moreover, a software system that integrates the parameter identification methodology was compiled and developed by using MATLAB and C++, which can provide a quick and efficient parameter identification process for engineering application in the future.

Motorcycle Tire Modeling for the Study of Tire–Rim Interaction

For the lightweight design of the wheel rim of motorcycles, the knowledge of the way in which contact forces are transmitted by the tire is of crucial importance. In this paper, an analytical model of the tire is developed and explicit formulae giving the distribution of the radial and axial forces acting on the wheel rim for a given vertical load are derived. The analytical model is validated by means of a finite element method (FEM) model and experimental tests. The proposed analytical model is able to predict the radial deflection of both a front and a rear tire for a racing motorbike with very good accuracy over a wide range of inflating pressures and vertical loads. The force distributions are in very good agreement with the results of the FEM model. Experimental tests show that the force distribution at the interface between the tire and rim can be used to predict the stress distribution in the rim with a good accuracy.