Tire-wheel Assembly Research Articles

Active Vibration Control on a Tire-Wheel Assembly using Piezoelectric Spatial Modal Filter

Abstract Vibrations due to tire-road contact in wheeled vehicles induce acoustic discomfort especially beyond 35 km·h−1. This paper proposes an active control method to reduce the vibration transmission from the tire-road contact to the vehicle through piezoelectric transducers located directly on the wheel spokes. Our approach relies on a double spatial modal filter to physically focus the control energy on the wheel pumping mode while avoiding any spillover phenomena. In addition, a band pass controller ensures maximum damping on the targeted mode. The proposed control strategy is applied first to the clamped wheel in order to validate the static performance of the spatial controller. Then the wheel is excited through the tire and the efficiency of the controller is evaluated through the measured force passing by the wheel hub. Finally, the tire-wheel assembly (TWA) is placed on an experimental set-up recreating the vehicle operating conditions with wheel rotation at different velocities and road excitation. The experimental results confirm the efficiency of the proposed control method and its robustness to the dynamics evolution of the structure in function of the TWA angular velocity.

On the relationship between the vibration characteristics of the automobile wheel and generated road noise in the vehicle cabin

The relationship between vibration characteristics of an automobile wheel and the generated road noise in the vehicle cabin was investigated experimentally and numerically because it is one of the vibration transmission paths caused by the input force from roads. Experiments were conducted using 15-inch wheels in two different vibration characteristics, and the results were discussed based on the measurements of the noise in the cabin and vibrational acceleration of the sub-frame of the vehicle when driving on smooth and rough roads at a speed of 30 km/h. Further, transient analysis using FEM was also performed using a tire-wheel assembly model. The results showed that large differences were observed in the generated noise of 49, 90, and 167 Hz in the case of the smooth road, and these differences were due to the difference in the magnitude of vibrational accelerations of the wheel at these frequencies.

Ride Comfort Analysis of Motor Vehicles using Analytical and Experimental Procedures

The occupants of an automobile are subjected to varying levels of vibration, which may not affect them consciously, but passively these are found to contribute to lower back pain, dizziness and discomfort amongst other health hazards when exposed for a chronic period. The primary source of these vibrations apart from the ones originating from the engine, are transmitted from the road during tire road interaction. The effect of this is felt by the occupants via the seat, foot rest, back rest and steering wheel of a four wheeler and the handlebar, footrest and seat in case of a two wheeler. The international standards such as ISO 2631-1:1997 for whole body are followed by vehicle manufacturers for ensuring ride comfort in terms of vibration transmissibility to the occupants. The ride comfort of a vehicle is influenced by the natural and force transfer characteristics of the tire wheel assembly and the suspension system. The objective of the current work is to use analytical models for finding natural frequencies of sprung and unsprung mass and henceforth determining the trend of vibration amplitude influenced by parameters like damping, mass and stiffness values through a forced response analysis. Subsequently, experiments are conducted to measure the real time vibration levels at aforementioned human interaction points. This helps to correlate the analytical study with the experimental outcomes.

Design of Helmholtz resonator group in a lightweight aluminum alloy wheel for reducing tire acoustic cavity resonance noise

Tire acoustic cavity resonance (TACR) noise is one of the significant sources causing vehicle interior noise at low-frequency band. Since the rotating and loading conditions can split TACR frequencies, TACR noise exhibits a relatively narrow frequency band, which becomes a challenge to attenuate this type of noise. To deal with this problem, the reduction method of the Helmholtz resonator (HR) group installed inside a lightweight aluminum alloy wheel is adopted in this paper. By the combination welding of spoke and rim in aluminum alloy wheel of a passenger vehicle, the internal annular hollow area is generated as the installation space for this HR group. Great advantages of this manufacturing process are the lightweight and easy installation performances for the wheel. According to the theoretical analyses based on the superposition of traveling waves and its experimental validations, the frequency bands of TACR noise for a rotating tire are determined. To reduce the noise, HR group consisting of 5 different sizes is designed by the Finite Element Method (FEM). Meanwhile, the sound-reducing tire-wheel assembly incorporated with the designed HR group is manufactured and tested by the bench and vehicle experiments. A remarkable reduction can be observed at the peak and specified frequency range of TACR noise. Moreover, the performance also proves to be stable and robust under various road and speed conditions. This paper provides a comprehensive and feasible process strategy for the development of noise-reducing wheel.

Research on mechanism and evolution features of frequency split phenomenon of tire acoustic cavity resonance

The acoustic cavity resonance inside the tire–wheel assembly is known to contribute to audible noise in the passenger compartment of vehicles. To obtain control methods of tire acoustic cavity resonance, its characteristics and producing mechanism need to be clarified first. In this article, the finite element model of a tire coupled with acoustic medium in the tire cavity is constructed. The Euler method is introduced to study the modal characteristics of tire cavity under the influence of tire inflation pressure, load, and tire rotation velocity. Frequency splitting phenomena under four separate conditions (stationary tire without load, stationary tire with load, rotating tire without load, and rotating tire with load) are simulated and analyzed. The slope change of the resonance frequency as a function of rotation speed is found to be close to the reciprocal of tire radius which can be explained by a model of wave propagation in a ring-shaped channel with moving media inside the ring. The obtained function of the slope change can help determine the frequency variation range under different vehicle velocity, structure load, and tire inflation pressure, which can then help to control the cavity resonance energy and provide a more comfortable driving experience.

Experimental analysis of sound field in the tire cavity arising from the acoustic cavity resonance

The acoustic cavity resonance noise inside the tire-wheel assembly is known to contribute to audible noise in the passenger compartment of vehicles, but it is difficult to attenuate the effect of tire cavity resonance noise. The purpose of this paper is to experiment and analyze the sound field in the tire cavity of a revolving tire through a customized sound pressure sensor fixed on the inner surface of the tire, and to obtain the distribution and frequency characteristics of sound field. Furthermore, the paper concerns the effects of the inflation pressure, the running velocity, and the load on the sound pressure distributions and its frequency characteristics, and the influence of these parameters are analyzed. The research is helpful to understand and attenuate the tire acoustic cavity resonance.

An improved structural-acoustic coupling model for tire cavity noise

Tire acoustic cavity resonance inside the tire-wheel assembly causes a tonal noise typically in the range of 190â–“250 Hz, which is an important source of vehicle interior noise. An analytical model considering cavity resonance is required for noise and vibration reduction; however, existing models require improvements, such as the consideration of composite properties and sidewall elasticity of the rubber-based tire. A new analytical tire model incorporating cavity resonance is proposed in this work. The tire is modeled as an annular cylindrical shell made of composites with elastic foundations rather than the typical isotropic shell with rigid simply supported boundary conditions. A unified numerical method with all nine sets of possible solutions for the vibration characteristic equation is applied to avoid missing solutions in conventional practices, as no available analytical solution for the problem exists. Modal results obtained through this model are in satisfactory agreement with the experiment, generally with less than 10% error. It is found that frequency response functions (FRFs) match with experiments basically. The effects of cavity resonance on the spindle force and moment were also very pronounced, through which the level of tire cavity noise can be reflected. While FRFs show peak values in both first and second cavity modes, the force response at the spindle has no apparent peak around the second tire cavity resonance, confirming the previous findings. The proposed model provides a sound theoretical formulation for tire cavity resonance and will also be an efficient quantitative tool for tire noise and vibration reduction.

A Simple Explicit Meta-Model for Probabilistic Design of Dynamic Systems with Multiple Mixed Inputs

Most systems have multiple inputs that comprise of a mixture of excitations and component parameters. Excitations are different from component parameters in that they are always functions of time. In mechanical systems, these include applied forces, applied displacements, system settings, systems configurations and operating conditions. It would be convenient to include multiple excitations and multiple component parameters in a meta-model to take advantage of the inherent computation speed needed for timely probability-based design optimization. In the development of the meta-model in this paper, we treat the component parameters in the same manner as the excitations and thus, in both cases, form time-sampled vectors. A design-of-experiments training regime creates a single input matrix, and using the mechanistic model, a single output matrix. Finally, a simple, explicit, meta-model is developed that turns an arbitrary vector of contiguous multiple excitations and multiple component parameters into the corresponding output vector (herein, the response). The approach provides an appealing and efficient solution to the multiple, mixed input problem, and in addition, requires only off-the-shelf computer software. The efficacy of the meta-model is shown through probability-based design optimization (PBDO) of a tire-wheel assembly, modelled as a mass-spring-damper system with nonlinear hysteresis, under a combination of practical inputs.

Motorcycle Analytical Modeling Including Tire–Wheel Nonuniformities for Ride Comfort Analysis

ABSTRACT The transmission of vibrations in motorcycles and their perception by the passengers are fundamental in comfort analysis. Tire nonuniformities can generate self-excitations at the rotational frequency of the wheel and contribute to the ride vibration environment. In this work a multi-body motorcycle model is built to evaluate the ride comfort with respect to tire nonuniformities. The aim is to obtain a multi–degrees-of-freedom dynamic model that includes both the contributions of the motorcycle and tire–wheel assembly structures. This representation allows the tire nonuniformities to predict the vertical force variations on the motorcycle and can be used through a root mean square acceleration evaluation for ride comfort analysis. The motorcycle model proposed is a 10-degrees-of-freedom system, where each tire–wheel is a 4-degrees-of-freedom model. The tire–wheel assemblies include two types of nonuniformities: lumped mass imbalance and radial run-out. Simulations of analytical models are compared with experimental tests.

Odd-Mode-Excited Tire-Wheel Assembly for Tire Pressure Monitoring Systems

A design methodology based on an odd-mode excited tire-wheel assembly is presented for tire pressure monitoring systems. The tire-wheel assembly is investigated using the finite-integration technique-based simulator CST Microwave Studio. Numerical investigations using a pair of electrically small dipoles inside the tire-wheel assembly show that the odd-mode excitation provides in-phase magnetic currents of standing waves along the angular direction on both sides of the tire-wheel assembly, resulting in the strong radiation in the plane normal to its axis. It is also shown that the odd-mode is excited by an electrically small loop antenna that has the aperture normal to the angular direction to enhance the magnetic coupling. The validity of the numerical investigations is confirmed by the measurements of a commercially available tire-wheel assembly at 434 MHz, where a loop antenna is installed into a transmitter. The effectiveness of the odd-mode excitation is numerically confirmed in a car body model having the tire-wheel assemblies rotated on the ground.

Tire wheel assembly and noise-reducing device

Disclosed are a tire wheel assembly and a noise-reducing device whereby cavity resonance sound can be effectively reduced. A noise-reducing device, which includes a shell structure where a rough surface portion having a ten-point height of irregularities (Rz) in a range of 0.1 to 5.0 mm is provided on at least part of a surface, is attached to a wheel rim in a cavity portion of a pneumatic tire, and additionally, a height of the shell structure from a rim sheet is set in a range of 10 to 70% of a cross-sectional height of the tire.

타이어의 첫 번째 공기공동 공명에 관한 유한요소해석

Vehicle interior noise is the results of numerous sources of excitation. One source involving tire pavement interaction is the tire cavity resonance and the forcing it provides to the vehicle spindle. Using a simplified model for the tire acoustic cavity system only, we formulated finite element equation to predict the fundamental acoustic cavity resonant characteristics inside tire-wheel assembly of undeformed and deformed tire. Combining the finite element analysis with experimental verification, we explained the acoustic characteristics theoretically. Especially, we have shown that the difference between the first two resonant frequencies increases as the deformation of deformed tire increases.

Simulation of wheel impact test using finite element method

In order to achieve better quality, the wheel design and manufacturing use a number of wheel tests to ensure that the wheel meets the safety requirements. The impact performance of wheel is a major concern of new design wheel. The wheel impact test is intended to evaluate the impact performance of wheel, that the striker is dropped from a specified height above the tire–wheel assembly. In this study, nonlinear dynamic finite element is used to simulate the SAE wheel impact test. The wheel modeled as an elastic–plastic body is mounted at an incline of 13° to horizontal, and the striker is prescribed an initial velocity to simulate a drop height. The total plastic work concept of ductile fracture mechanics is used to predict the impact failure of wheel. Three-dimensional finite element method is employed to obtain the strain energy density of wheel at impact, and the critical strain energy density is based on the total plastic work of wheel material. Compared with actual tests, the finite element results show the total plastic work approach can be used to predict the wheel fracture during the impact test.

Theoretical analysis of tire acoustic cavity noise and proposal of improvement technique

This paper describes an investigation into interior road noise caused by the acoustic cavity resonance inside the tire–wheel assembly when a passenger car is running. First of all, we researched some characteristics of the acoustic cavity resonance inside the tire–wheel assembly. Next, we derived the equation of motion of the acoustic cavity system and explained the characters theoretically. Then, we proposed a technique to reduce the peak level of the acoustic cavity natural frequency. Finally, we made prototype wheels and confirmed their validity.

Influence of Rim Run-Out on the Nonuniformity of Tire-Wheel Assemblies

Abstract An analytical membrane model is used to study how wheel imperfections are converted into radial force variation of the tire-wheel assembly. This model indicates that the radial run-out of the rim generates run-out of the tire-wheel assembly at slightly less than the one to one ratio that was expected. Lateral run-out of the rim is found to generate radial run-out of the tire-wheel assembly at a ratio that is dependent on the tire design and the wheel width. Finite element studies of a production tire validate and quantify the results of the membrane model. Experiments using a specially constructed precision wheel demonstrate the behavior predicted by the models. Finally, a population of production tires and wheels show that the lateral run-out of the rims contribute a significant portion to the assembly radial force variation. These findings might be used to improve match-mounting results by taking lateral rim run-out into account.

Force Transmissibility of Heavy Truck Tires

Abstract A laboratory study of force transmission in radial truck tires is described. The experiments are conducted with the tire-wheel assembly attached to a fixed, nonrotating axle. Contact with the tire is provided by a flat surface. Single frequency displacement cycles are applied to the loaded tire footprint, and the dynamic force transmitted through the tire is measured at the fixed axle. Fourier transform signal analysis is used to extract the cyclic displacement and force amplitudes. The amplitude ratio force/displacement is defined as the force transmissibility. The experiments show inflation pressure and tire load to have little effect on force transmissibility. A single degree of freedom tire model for force transmissibility is described. The model uses easily measured tire parameters and is intended for use in vehicle models to include the effect of tire dynamics.

Fore-Aft Forces in Tire-Wheel Assemblies Generated by Unbalances and the Influence of Balancing

Abstract When measuring bearing forces of the tire-wheel assembly during drum tests, it was found that beyond certain speeds, the horizontal force variations or so-called fore-aft forces were larger than the force variations in the vertical direction. The explanation of this phenomenon is still somewhat an open question. One of the hypothetical models argues in favor of torsional oscillations caused by a changing rolling radius. But it appears that there is a simpler answer. In this paper, a mathematical model of a tire consisting of a rigid tread ring connected to a freely rotating wheel or hub through an elastic foundation which has radial and torsional stiffness was developed. This model shows that an unbalanced mass on the tread ring will cause an oscillatory rolling motion of the tread ring on the drum which is superimposed on the nominal rolling. This will indeed result in larger fore-aft than vertical force variations beyond certain speeds, which are a function of run-out. The rolling motion is in a certain sense a torsional oscillation, but postulation of a changing rolling radius is not necessary for its creation. The model also shows the limitation on balancing the tire-wheel assembly at the wheel rim if the unbalance occurs at the tread band.

High-speed braking of an aircraft tire on grooved surfaces

The Federal Aviation Administration is engaged in an experimental program to determine the effectiveness of grooves and other low-cost surface treatments that alleviate hydroplaning. A ground test facility provides speeds of up to 150 knots by the use of a jet-powered pusher car that also supports a tire-wheel assembly. The tires of a Boeing 727 aircraft are inflated to 140 psi and loaded vertically to 35,000 Ib. The tire-runway braking is measured by the use of proper instrumentation. High-speed braking tests show that low-cost surface treatment can be provided in two ways: 1) by increasing the spacing of the square saw-cut grooves beyond 11A in., and 2) by installing V-shaped grooves using a reflex-percussive cutting process. In both cases, the braking effectiveness of an aircraft tire was found to be acceptable and hydroplaning was not experienced at speeds of up to 150 knots.

Uniformity of Tires at Vehicle Operating Speeds

Abstract The general trend of the forces generated by a nonuniform tire and wheel as a function of speed has been available for several years. As a rule it has been found that the first harmonic of the force variation is the greatest single contributory factor in those vehicle shake problems originating at the tire and wheel. The paper shows how the first harmonic varies with speed for a batch of tires, and, in particular, discusses the phase and amplitude relationship between longitudinal force variation and radial force variation with speed; a mathematical analysis is given. Attempts to counteract the high speed nonuniformity forces by using balance weights on the wheel are reported. The relative effect of the tire and the wheel is considered. Also, the application of this work as a vehicle shake diagnostic technique to isolate tire wheel assembly and vehicle effects is discussed.