Flexible Tire Research Articles

Optimization and improving of the production capacity of a flexible tyre painting cell

AbstractOptimization of industrial processes is a constant concern and a main task for many companies in several industry sectors. Based on optimized solutions, the company can decrease manufacturing costs, lead times or, more generally, increase benefit. However, when developing a new process, you must be sure that the new solution will add more value to the initial solution. This, among many others, is one of the main reasons why companies opt, in addition to experimentation, for the use of tools that allow for the virtual prototyping, simulation, and integration of complex and sophisticated processes. Experimentation requires approximation testing, searching for the ideal values of quantity, temperature, etc.; simulation provides industrial processes with test support ranging from flows to robotic systems such as the intelligent software. This simulation software allows to develop programs, add Computer Aided Design (CAD) layouts, and simulate the cycle times of the different tasks to be performed. In this paper, an experimental approach is presented with atomization and fan spray pressure as the study basis and a simulation of the robot-based handling solution used in a tyre production line. The result is an improvement of the painting process, optimisation of the amount of fluid deposited on the tyre, of the processed product, as well as of the running times of the robot.

Modelling and analysis of intelligent tyre alternatives for better performance

For more than ten decades people have been using vehicles rolling on pneumatic tyres. The essential factor for safety of automobile is tyre. Tyre conditional plays vital role in the safety of a passenger. In olden days wheels were made up of wood, later it became evolved into tube and tubeless tyre. A traditional tire is made up of reinforced rubber packed by using compressed air. Conventional tyre over period had been dominating market sector because of its riding comfort and strength. But it has its own disadvantages like problems of puncture, inflation. Under or over inflation of tyre cancause tire blowouts, tread separation. In recent years a few tyre companies and researchers are experimenting with non-pneumatic tyre performance including Michelin, Bridgestone, and goodyear but none of them has started its mass production. Non pneumatic tyres are the tyres which no longer need air pressure. In this project we replace traditional tyre by flexible tyre structure and finds out other intelligent alternatives to conventional tyres. We have investigated spoke’s structure designed for airless tyre and applied uniaxial load. We designed the structure in ANSYS design modeler and ANSYS static structural has been used to analyze whether the designed structure is valid or not. Three kinds of intelligent tyre alternatives have been identified and stressed their use, working and importance for future mobility.

Dynamic Response of a Vehicle-Bridge Expansion Joint Coupled System

The paper investigates the dynamic vibration property of the vehicle-bridge expansion joint coupled system with the proposed model. The dynamic response of the expansion joint under the action of the vehicle is the key factor affecting the life of the expansion joint. The changes of contact state and tire geometric characteristics were frequently left aside in the past to simplify the tire model. This is because the contact between tire and expansion joint is a very complex process. But this will seriously underestimate the impact effect of the vehicle on the expansion joint. In this paper, a dynamic mathematical model of the 2-axle vehicle-modular bridge expansion joint (MBEJ) coupled system is established by introducing a flexible roller tire model. The influence of tread rigid displacement and change in the tire contact patch length are considered in the dynamic model. Based on this model, the characteristics of the dynamic tire load and the center beam vibration displacement in the coupled system are obtained by simulation. The results show that the maximum dynamic tire load of the vehicle occurs at the end of the bridge deck behind the MBEJ, so local structure reinforcement needs to be considered. The interaction between the front and rear wheels of the 2-axle vehicle can be ignored. The vehicle position, vehicle velocity, gap width, and spring stiffness of the center beam bearing have significant effects on the impact factors of tire load and center beam vibration displacement. The impact factor of tire load may exceed the recommended values of Chinese and European bridge codes. These should be taken seriously.

Multiple solutions and transient chaos in a nonlinear flexible coupling model

This paper investigates the nonlinear dynamics of a flexible tyre coupling via computer modelling and simulation. The research mainly focused on identifying basins of attraction of coexisting solutions of the formulated phenomenological coupling model. On the basis of the derived mathematical model, and by assuming ranges of variability of the control parameters, the areas in which chaotic clutch movement takes place are determined. To identify multiple solutions, a new diagram of solutions (DS) was used, illustrating the number of coexisting solutions and their periodicity. The DS diagram was drawn based on the fixed points of the Poincaré section. To verify the proposed method of identifying periodic solutions, the graphic image of the DS was compared to the three-dimensional distribution of the largest Lyapunov exponent and the bifurcation diagram. For selected values of the control parameter ω, coexisting periodic solutions were identified, and basins of attraction were plotted. Basins of attraction were determined in relation to examples of coexistence of periodic solutions and transient chaos. Areas of initial conditions that correspond to the phenomenon of unstable chaos are mixed with the conditions of a stable periodic solution, to which the transient chaos is attracted. In the graphic images of the basins of attraction, the areas corresponding to the transient and periodic chaos are blurred.

Influence Analysis of Machining and Installation Errors on the Radial Stiffness of a Non-Pneumatic Mechanical Elastic Wheel

Machining and installation errors are unavoidable in mechanical structures. However, the effect of errors on radial stiffness of the mechanical elastic wheel (ME-Wheel) is not considered in previous studies. To this end, the interval mathematical model and interval finite element model of the ME-Wheel were both established and compared with bench test results. The intercomparison of the influence of the machining and installation errors on the ME-Wheel radial stiffness revealed good consistency among the interval mathematical analysis, interval finite element simulation, and bench test results. Within the interval range of the ME-Wheel machining and installation errors, parametric analysis of the combined elastic rings was performed at different initial radial rigidity values. The results showed that the initial radial stiffness of the flexible tire body significantly influenced the ME-Wheel radial stiffness, and the inverse relationship between the hinge unit length or suspension hub and the radial stiffness was nonlinear. The radial stiffness of the ME-Wheel is predicted by using the interval algorithm for the first time, and the regularity of the radial stiffness between the error and the load on the ME-Wheel is studied, which will lay the foundation for the exact study of the ME-Wheel dynamic characteristics in the future.

Physics-Based Flexible Tire Model Integrated With LuGre Tire Friction for Transient Braking and Cornering Analysis

In transient vehicle maneuvers, structural tire deformation due to the large load transfer causes abrupt change in normal contact pressure and slip distribution over the contact patch, and it has a dominant effect on characterizing the transient braking and cornering forces including the history-dependent friction-induced hysteresis effect. To account for the dynamic coupling of structural tire deformations and the transient tire friction behavior, a physics-based flexible tire model is developed using the laminated composite shell element based on the absolute nodal coordinate formulation and the distributed parameter LuGre tire friction model. In particular, a numerical procedure to integrate the distributed parameter LuGre tire friction model into the finite-element based spatial flexible tire model is proposed. To this end, the spatially discretized form of the LuGre tire friction model is derived and integrated into the finite-element tire model such that change in the normal contact pressure and slip distributions over the contact patch predicted by the deformable tire model enters into the spatially discretized LuGre tire friction model to predict the transient shear contact stress distribution. By doing so, the structural tire deformation and the LuGre tire friction force model are dynamically coupled in the final form of the equations, and these equations are integrated simultaneously forward in time at every time step. The tire model developed is experimentally validated and several numerical examples for hard braking and cornering simulation are presented to demonstrate capabilities of the physics-based flexible tire model developed in this study.

Longitudinal Tire Dynamics Model for Transient Braking Analysis: ANCF-LuGre Tire Model

In this investigation, the flexible tire model based on the absolute nodal coordinate formulation (ANCF) is integrated with LuGre tire friction model for evaluation of the longitudinal tire dynamics under severe braking scenarios. The ANCF-LuGre tire model developed allows for considering the nonlinear coupling between the dynamic structural deformation of the tire and its transient tire force distribution in the contact patch using general multibody dynamics computer algorithms. To this end, the contact patch obtained by the ANCF elastic ring tire model is discretized into small strips and the state of friction at each strip is defined by the differential equation associated with the discretized LuGre friction parameters. The normal contact pressure distribution predicted by the ANCF elastic ring elements that are in contact with the road surface are mapped onto the LuGre strips in the contact patch to evaluate the tangential tire force distribution and then the tire forces evaluated at LuGre strips are fed back to the generalized tangential contact forces of the ANCF elastic ring tire model. By doing so, the structural deformation of the ANCF elastic ring tire model is dynamically coupled with the LuGre tire friction in the final form of the governing equations. Furthermore, the systematic and automated parameter identification procedure for the LuGre tire force model is developed. It is shown that use of the proposed procedure with the modified friction curve proposed for wet road conditions leads to accurate prediction of the LuGre model parameters for measured tire force characteristics under various loading and speed conditions. Several numerical examples are presented in order to demonstrate the use of the in-plane ANCF-LuGre tire model for the longitudinal transient dynamics of tires under severe braking scenarios.

Wheel slip phenomena

A new approach is given to explain vehicle tyre slip phenomena. With this approach the term 'wheel slip', as used by engineers in connection with off–road machines, covers four different physical phenomena which we call respectively slip of the first, second, third and fourth type. Three of these phenomena do not involve the actual slipping of a tyre on a surface and, in addition, two of them are not essentially slipping. The main attention is focused on the components of slip which can explain the experimental deviation of a flexible tyre behaviour from zero slip without any sliding at the tyre–surface contact zone. Based on this interpretation of the slip phenomena, an explanation of the well known experimental relationships between pull (thrust) and slip is discussed. This new approach is used for the development of a vehicle ride simulation computer system.

Development of a 3-D quasi-static tyre model for on-road and off-road vehicle dynamics simulations: Part I - on-road flexible tyre model

The research conducted in this study deals with the development of a simplified brush-based tyre model for on-road simulation, together with a simplified off-road wheel/tyre model. The on-road tyre model is developed based on data collected by NHTSA throughout the years, while the off-road tyre model is developed based on observations of experimental data and photographic evidence collected by various terramechanics researchers within the last few decades. The principle behind the model revolves around the integration of the stresses at the contact interface and has its basis in terramechanics. The model was parameterised from test data to acquire static and dynamic friction coefficients, cornering and longitudinal stiffness, as well as camber stiffness. The results are compared with test data and show good correlation. This paper is the first of a series of three papers on the modelling tyres for both on- and off-road operations.

Development of a 3-D quasi-steady state tyre model for on-road and off-road vehicle dynamics simulations: Part III - off-road flexible tyre model

Development of a 3-D quasi-steady state tyre model for on-road and off-road vehicle dynamics simulations: Part III - off-road flexible tyre model

Analysis of Influence for Steering Performance of Vehicle on Road Surface Roughness

It is very important that the flexible tires have some effects on the movement of the vehicle. To analyze the influence of the flexible tire on different road surface roughness in the steering movement of the vehicle, the paper cites the traditional two degrees of freedom (2-DOF) model for steering movement of vehicle, analyzes deformation of the tires when the flexible tires scroll on the hard and soft road surface. The paper establishes mechanical model about the relationship of the tires and different road surface, and advances mathematics equation in the typical 2-DOF model. To verify theoretical derivation the tests of steering motion of the vehicle are done on the different road surface roughness.The results show that yaw rate of the vehicle is very different on the soft and hard road surface when the vehicle steers along the same turning radius path and at the same speed. The results illustrate that analysis of theory is right.

Simulation of Vehicle Dynamic Stability on Ro-Ro Ship Using MHS Measurement

By modeling ship motion using PM wave spectrum and strip theory, and modeling vehicle as rigid chassis and flexible tire, the dynamics equation of ship and vehicle multi-body system is developed using Lagrange equation. The numerical solution of equation shows the forces between tire and deck contact are impacted by ship motion. To compare the possibility of tip over around different axes, a Moment-Height Stability (MHS) measure method is used to calculate the stability of vehicle on the deck. The MHS result shows compartments of the instability around each edge, which is a good supplement to the tire force method.

A tyre-terrain interaction model for off-road vehicles

The problem of off-road vehicle tyre - terrain interaction is difficult enough to be accurately solved. The previous work of many researchers pointed the terramechanics engineers into the right direction and a variety of methods to the study of tyre - terrain interaction has been developed over the last decades, they range from the entirely empirical to the highly theoretical. In this paper, a mathematical model based on mechanical spring mass-damper system was used to simulate the tyre- terrain interaction. A terrain mechanical model was developed to simulate the soil deformation under the effect of flexible tyre loading. A computer program using MATLAB/Simulink software was developed to solve the new model. The simulation shows that the new tyre - terrain model provides satisfactory results than the old one. Based on the obtained results, it is evident that the proposed model represents a step forward that enables better understanding of tyre - terrain interaction. Key words: Tyre - terrain interaction, soil modeling, off-road vehicle.

Off-road tire modeling and the multi-pass effect for vehicle dynamics simulation

Off-road operations are critical in many fields and the complexity of the tire-terrain interaction deeply affects vehicle performance. In this paper, a semi-empirical off-road tire model is discussed. The efforts of several researchers are brought together into a single model able to predict the main features of a tire operating in off-road scenarios by computing drawbar pull, driving torque, lateral force, slip-sinkage phenomenon and the multi-pass behavior. The approach is principally based on works by Wong, Reece, Chan, and Sandu and it is extended in order to catch into a single model the fundamental features of a tire running on soft soil. A thorough discussion of the methodology is conducted in order to highlight strengths and weakness of different implementations. The study considers rigid wheels and flexible tires and analyzes the longitudinal and the lateral dynamics. Being computationally inexpensive a semi-empirical model is attractive for real time vehicle dynamics simulations. To the best knowledge of the authors, current vehicle dynamics codes poorly account for off-road operations where tire-terrain interaction dominates vehicle performance. In this paper two soils are considered: a loose sandy terrain and a firmer loam. Results show that the model realistically predicts longitudinal and lateral forces providing at the same time good estimates of the slip-sinkage behavior and tire parameters sensitivity.

Finite element modeling of interfacial forces and contact stresses of pneumatic tire on fresh snow for combined longitudinal and lateral slips

Significant challenges exist in the prediction of interaction forces generated from the interface between pneumatic tires and snow-covered terrains due to the highly non-linear nature of the properties of flexible tires, deformable snow cover and the contact mechanics at the interface of tire and snow. Operational conditions of tire–snow interaction are affected by many factors, especially interfacial slips, including longitudinal slip during braking or driving, lateral slip (slip angle) due to turning, and combined slip (longitudinal and lateral slips) due to brake-and-turn and drive-and-turn maneuvers, normal load applied on the wheel, friction coefficient at the interface and snow depth. This paper presents comprehensive three-dimensional finite element simulations of tire–snow interaction for low-strength snow under the full-range of controlled longitudinal and lateral slips for three vertical loads to gain significant mechanistic insight. The pneumatic tire was modeled using elastic, viscoelastic and hyperelastic material models; the snow was modeled using the modified Drucker–Prager Cap material model (MDPC). The traction, motion resistance, drawbar pull, tire sinkage, tire deflection, snow density, contact pressure and contact shear stresses were obtained as a function of longitudinal slip and lateral slip. Wheel states – braked, towed, driven, self-propelled, and driving – have been identified and serve as key classifiers of discernable patterns in tire–snow interaction such as zones of contact shear stresses. The predicted results can be applied to analytical deterministic and stochastic modeling of tire–snow interaction.

On Engine-to-Slip Modelling for Motorcycle Traction Control Design

Tyre and transmission characteristics affect engine-to-slip dynamics which are essential when it comes to traction control design. This paper uses different tyre/transmission physical models to assess the modelling features which are essential for an accurate description of the plant. Three different single-wheel models are presented and analysed in order to find the simplest, yet reliable, model for the description of the engine-to-slip dynamics. The models are a single-wheel model with a rigid tyre and a rigid transmission, a single-wheel model with a flexible tyre, and a single-wheel model which features a compliant tyre and a sprocket absorber. Analytic expressions for all models' transfer functions are given, and models are compared to each other and with road tests to prove their reliability. Finally, the effect of longitudinal acceleration on engine-to-slip dynamics is analysed and discussed.

Non-linear elastic ring tyre model using the absolute nodal coordinate formulation

In this investigation, a non-linear elastic ring tyre model is developed. The elastic deformation of the tyre belt is modelled using the finite element absolute nodal coordinate formulation that allows for describing large rotational motion and the non-linear inertia effects; the curved structure of the tyre belt; and moving boundary resulting from the tread and road interaction. Using a concept of elastic ring tyre models, the sidewall flexibility of a tyre is modelled using circumferential and radial springs and dampers defined between the belt and rim, while the tangential tyre force is modelled using friction elements defined at contact nodes defined within the curved belt elements. Numerical examples are presented in order to demonstrate the use of the flexible tyre model developed in this investigation. Good agreements are demonstrated in the tyre vibration characteristics obtained using the experiments and the proposed model. It is presented that the proposed tyre model can be used for assessing dynamic characteristics of tyres in high frequency ranges resulting from the interaction to uneven road surfaces.

Lateral Response of Nonlinear Nose Wheel Landing Gear Models with Torsional Free-play

Nose-wheel landing gears can, under certain conditions, exhibit instability in lateral dynamics, causing divergent coupled lateral flexural and torsional oscillations called shimmy. The stability of the system depends on the dynamic characteristics of the gear and tires, nonlinearities in the system, and vibratory modes of the vehicle as a whole, as well as the degree of coupling that exists between them. Shimmy may be caused by a number of conditions such as low torsional stiffness of the strut, free play in the gear, wheel imbalance, or worn parts. Free play in the steering degree of freedom has the potential to significantly reduce the divergent shimmy velocity. Nonlinear behavior of landing gear makes the evaluation of the shimmy phenomenon more complex and its prediction more difficult. This work presents a study of the shimmy instability of a three-degree-of-freedom simplified nose-wheel landing gear model with linear flexible tire model and nonlinearities arising out of torsional free play. Response results are presented for a typical range of values of various problem parameters. Numerical studies bring out several interesting features of the shimmy and its dependence on free play.

Flexible Crumb Tire Rubber-Filled Cement Mortars as a Protective System for Buried Infrastructure

Abstract Due to population growth and urban congestion, the space available for the development of public infrastructure is sharply decreasing. Engineers are therefore resorting to the efficient use of underground space, which involves the construction of tunnels and other underground structures. Many such projects will be located in rock/soil with time-dependent behavior or under high overburden pressure. Thus, under such stress conditions, there may be a need for a deformable supporting system that can serve as a buffer layer to protect tunnel linings from time-dependent deformations of the excavated rock/soil. This paper investigates the use of cement mortars containing crumb recycled tire rubber to develop a flexible interface material for such applications. The effects of the w/c ratio, rubber content, and particle size on the mechanical properties of rubber filled mortars were studied using uniaxial and triaxial compression tests. A statistical factorial experimental plan was designed to obtain response surfaces for the parameters under study. A model tunnel was made, instrumented, and tested in a specially designed pressure cell under hydrostatic pressure to investigate the effect of using flexible rubber-filled mortar layers around tunnel linings on the development of stresses. The findings of this research suggest that cement mortars containing crumb tire rubber have superior ductility and may be used to accommodate deformations around tunnel linings, pipelines, and other buried infrastructure.

Tractive performance of a tread design for improved flexibility

The tractive performance of an 18.4R38 radial-ply tractor tire with increased flexibility in the tread area was compared to that of a standard tread design. Normal soil-tire interface stresses were measured at four locations on the lug surfaces of both tires operating on Decatur clay loam and Norfolk sandy loam soils. There was a tendency for the increased flexibility in the tread area to provide a higher net traction ratio at the same tractive efficiency as the standard tread design, especially on Decatur clay loam soil. The more flexible tread design reduced the magnitude of peak normal contact stresses across the tire width, which may have implications for reducing soil compaction without compromising tractive performance. The more flexible tire reduced the average normal contact stress by approximately 15% in the sandy loam soil and 23% in the clay loam soil for the range of operating conditions investigated.