Tire Pattern Research Articles

Characteristics Analysis of Tire Hydroplaning Flow and Tread Design Influence Study

Tire hydroplaning has become a direct inducement of wet-weather road accidents. The model of hydroplaning of the deformed rib tire with load was built with the help of CFD (Computational Fluid Dynamics) technology. The three-dimensional SST coupled with the Volume of Fluid (VOF) model was applied to numerically simulate the air-water two phase flow with free surface in tire hydroplaning. Based on the model of hydroplaning, the design of tire pattern rib and lateral grooves on tire hydroplaning were analyzed. Analysis shows that tire has a high pressure induced by water impact in the front of footprint; water flow is inclined to tire sidewall. For the rib grooves, the depth of rib groove has a largest effect, followed by the rib groove width, finally the distance between the two rib grooves; for the lateral grooves, the structure factors sequence is :lateral grooves number> width> angle.

영상 신호 처리기술을 이용한 타이어 패턴 소음 예측 기술

Tire noise is divided into two parts. One is pattern noise the other one is road noise. Pattern noise primarily occurs in over 500 Hz frequency but road noise occurs mainly in low frequency. It is important to develop a technology to predict the pattern noise at the design stage. Prediction technology of pattern noise has been developed by using image processing. Shape of tire pattern is computed by using imaging signal processing. Its results are different with the measured one. Therefore, the prediction of actual measured pattern noise is valuable. In the signal processing theory is applied to calculate the impulse response for the measurement environment. This impulse response used for the prediction of pattern noise by convolving this impulse response by the results of image processing of tire pattern.

Characteristics of Vehicle Tire Tread Pattern and its Application in Forensic Science

Vehicle tire tread pattern is an important part of vehicle tire and also an important object concerned by the police workers who want to deduce or identify the suspected vehicle tire through the tire pattern impression left on the crime scene, which is routinely reflected by tire pattern impression on the surface tire rolled through. In this paper, the characteristics of vehicle tire pattern and its application in forensic science was analyzed and summarized in accordance with cases, based on the analysis of the process of production and using. The research indicated that the tire pattern not only has type characteristics corresponding to vehicle type, but also may have some new individual characteristics in the process of production and using in special condition. The morphological characteristics of tire pattern can be reflected more or less by the tire impression which left on road, clothes or body skin. With the development of trace extraction and enhancement technology, the morphological characteristics of tire pattern in tire impression will be used to deduce vehicle type or identify the suspected vehicle tire, which will play an important role in forensic evidence.

Investigation of the Influence of Tyre Geometry on the Aerodynamics of Passenger Cars

It is well known that wheels are responsible for a significant amount of the total aerodynamic drag of passenger vehicles. Tyres, and mostly rims, have been the subject of research in the automotive industry for the past years, but their effect and interaction with each other and with the car exterior is still not completely understood. This paper focuses on the use of CFD to study the effects of tyre geometry (tyre profile and tyre tread) on road vehicle aerodynamics. Whenever possible, results of the numerical computations are compared with experiments. More than sixty configurations were simulated. These simulations combined different tyre profiles, treads, rim designs and spoke orientation on two car types: a sedan and a sports wagon. Two tyre geometries were obtained directly from the tyre manufacturer, while a third geometry was obtained from our database and represents a generic tyre which covers different profiles of a given tyre size. All geometries were deformed based on measured wind tunnel data under a defined load and rotating conditions of 100 kph. Results have shown that the main grooves consistently lead to a decrease of both drag and lift. The edge pattern however, did not show a clear trend for drag and lift with respect to the different configurations studied, although its influence was always more noticeable on the sports wagon. The larger profile of the generic tyre resulted in higher drag and lift values with relation to the tyres obtained from the manufacturer. For a given rim, a drag difference was observed between two tyre geometries with same profile but different tyre tread. These findings lead to the conclusion that tyre profile, as well as tyre pattern, are important to consider. These results were confirmed by wind tunnel tests. In conclusion, the work of aerodynamic optimization of rims cannot be separated from the tyre itself.

Research on the Manufacture of Multi-Sipe Radial Tire Molds by EDM

It is a technical challenge to insert sipes in a multi-sipe radial tire mold. The authors have invented a new method to make tire mold patterns by EDM which has solved the problems of inserting the sipes, characterized in that the patterns and sipes can be made at the same time, and as they are made as one body after EDM, there is no need to manually insert the sipes. The multi-sipe tire molds made by EDM meet the technical standards of famous international tire companies, and evaluation results show that this process works very well in the manufacture of complicated tire molds.

Influencing Factor of Hydrodynamic Pressure on Tire in Wet Weather Based on Fluent

AbstractHydrodynamic pressure is the major cause of vehicle hydroplaning in wet weather. By establishing a finite element model of the tire with longitudinal and transverse pattern, hydrodynamic pressure of the tire under different driving conditions and distributing pattern of water velocity in different parts of the tire were obtained through Fluent. The relations of hydrodynamic pressure with vehicle velocity, water film thickness, and tire pattern depth were gained based on data regression. The results show that (1) hydrodynamic pressure of the tire depends on water film thickness, tread pattern depth, and vehicle speed; (2) as water film thickness increases, the relation between hydrodynamic pressure and vehicle speed gradually shifts from non-linear to linear; and (3) influence of vehicle speed on hydrodynamic pressure is the most obvious, and changing the tread pattern depth alone cannot completely avoid hydroplaning.

Hydroplaning of Tire

The numerical procedure for hydroplaning was developed by considering the following three important factors; fluid/structure interaction, tire rolling, and practical tread pattern. The tire is analyzed by FEM with Lagrangian formulation and the fluid is analyzed by FVM with Eulerian formulation. Since the tire and the fluid are modeled separately and their coupling is automatically computed by the coupling element, the fluid/structure interaction of the complex geometry such as the tire with the tread pattern can be analyzed practically. The predictability was validated by comparing the hydroplaning simulation with the experiment on the subjects such as the water flow, the velocity dependence of hydroplaning, and the effect of the tread pattern on hydroplaning. In order to predict the streamline in the contact patch, the procedure of the global-local analysis was developed. The predicted streamline enabled us to develop the new tire pattern in a short period based on the principle; “make the stream line smooth”.

유전자 알고리즘을 이용한 타이어 공력소음의 저감

The paper presents the novel approach to solve some problems occurred in application of the genetic algorithm to the determination of the optimal tire pattern sequence in order to reduce the tire air-pumping noise which is generated by the repeated compression and expansion of the air cavity between tire pattern and road surface. The genetic algorithm has been used to find the optimal tire pattern sequence having a low level of tire air-pumping noise using the image based air-pumping model. In the genetic algorithm used in the previous researches, there are some problems in the encoding structure and the selection of objective function. The paper proposed single encoding element with five integers, divergent objective function based on evolutionary process and the optimal evolutionary rate based on Shannon entropy to solve the problems. The results of the proposed genetic algorithm with evolutionary process are compared with those of the randomized algorithm without evolutionary process on the two-dimensional normal distribution. It is confirmed that the genetic algorithm is more effective to reduce the peak value of the predicted tire air-pumping noise and the consistency and cohesion of the obtained simulation results are also improved in terms of probability.

Research on Vulcanization Process of Short Fiber-Rubber Composite Material

Vulcanization process is the last step of manufacturing rubber products. For tire tread which is made of short fiber rubber composite material, vulcanization is complex due to during vulcanization process the flow of mixed rubber maybe change short fibers orientation. As a result, during vulcanization process, several pieces of iron wire have been put in the mold to play the role of tire patterns for the first step research. The experimental results indicate that the flow of mixed rubber would not change short fibers orientation greatly, and physical and mechanical properties of short fiber-rubber composite material keep as good as that vulcanized without iron wire.

Application of Computational Mechanics to Tire Design—Yesterday, Today, and Tomorrow

Abstract The tire technology related with the computational mechanics is reviewed from the standpoint of yesterday, today, and tomorrow. Yesterday: A finite element method was developed in the 1950s as a tool of computational mechanics. In the tire manufacturers, finite element analysis (FEA) was started applying to a tire analysis in the beginning of 1970s and this was much earlier than the vehicle industry, electric industry, and others. The main reason was that construction and configurations of a tire were so complicated that analytical approach could not solve many problems related with tire mechanics. Since commercial software was not so popular in 1970s, in-house axisymmetric codes were developed for three kinds of application such as stress/strain, heat conduction, and modal analysis. Since FEA could make the stress/strain visible in a tire, the application area was mainly tire durability. Today: combining FEA with optimization techniques, the tire design procedure is drastically changed in side wall shape, tire crown shape, pitch variation, tire pattern, etc. So the computational mechanics becomes an indispensable tool for tire industry. Furthermore, an insight to improve tire performance is obtained from the optimized solution and the new technologies were created from the insight. Then, FEA is applied to various areas such as hydroplaning and snow traction based on the formulation of fluid–tire interaction. Since the computational mechanics enables us to see what we could not see, new tire patterns were developed by seeing the streamline in tire contact area and shear stress in snow in traction.Tomorrow: The computational mechanics will be applied in multidisciplinary areas and nano-scale areas to create new technologies. The environmental subjects will be more important such as rolling resistance, noise and wear.

The Study of Tire Pattern Noise by Using Wavelet Transform

Tire noise is classified by pattern noise and road noise in a vehicle. Especially pattern noise has impulsive characteristics since it is generated by impacting of tire’s block on the road. Therefore, a special signal process is needed other than traditional Fourier Transform, because the characteristic of signal is varying with time. On the other hand, the pattern noise is a kind of non-stationary signal and is related to the impulsive train of pitch sequence of a block. In this paper, Wavelet Transform is applied to verify the impulse signal caused by impact of block and groove and to verify the relationship between the pattern noise and the train of pitch sequence.

Analysis of Tire Tread Pattern’s Impact on Interior Vibration and Noise Based on Wavelet Transform

The path of tire pattern’s impact on interior noise and vibration was analyzed. The same type tires with six kinds of different tread pattern were selected as the investigating subjects, and the interior measuring points’ vibration and noise signals of different tires were measured under full load condition. The basic theory of Wavelet Transform (WT) and its signal reconstruction principle were researched, and 1/3 octave Morlet wavelet was induced and analyzed. The vibration and noise signals of measuring points were transformed by using 1/3 octave Morlet wavelet, distribution features of vibration and noise signals of six tires with different tread pattern were made a comparison in time domain and frequency domain, and the distinct results of different tires were achieved. The advantage of WT in the aspect of time-frequency analysis for time domain signal is revealed.

Study on Construction of Tyre Tread Pattern Mold and its Machining with 3-Axis Numerical Control

Tyre tread pattern mainly accounts for tyre performance and its endurance. In tyre mold processing, pattern block processing is technologically disturbing, of which the tread pattern is the most challenging. This article first analyses the function conversion of the points from point to plane to space along the tyre tread curve. Aided by GRIP language, it continues to make tread section with spatial curve, and then with the help of UG scanning order, it produces a three-dimensional diorama of accurate tyre pattern. To solve the problem of large errors arising in tyre mold processing with 3 axis numerical control technology, the article proposes a new method to produce tyre tread pattern with 3 axis technology and validates the method. The research contributes to dividing processing of tyre tread pattern, and reducing errors theoretically. Experiments had been done to illustrate that the method can achieve high quality and efficient processing.

Arithmetic of automatically forming meridian tire tread pattern on basis of unigraphics

Tire tread pattern affects the performance of motor vehicles and traffic safety; therefore, designing it accurately is very important. This paper mainly discusses the arithmetic that can form tire tread patterns automatically and rapidly. The algorithm flow is given. Then, the principle of planar picture creating three-dimensional patterns concretely is analyzed. The experimental results of the meridian tire pattern based on the UG API function prove the feasibility and excellence of the proposed method.

전동식 지게차의 진동저감에 대한 연구

In this paper, vibration sources of an electric forklift are identified and the forklift vibrations are reduced by structural modification. For vibration identification, vibration signals are measured by an accelerometer when the forklift is moving. These signals are presented in a waterfall plot in order to find the dependency of frequency components on the forklift speed. It is found that main vibration source is tire pattern excitation. From some experiments and finite element analyses, it is also found that resonances occur because the natural frequencies of the forklift exist in usual driving speed range. To shift the natural frequencies outside the driving speed range, the connection parts between main body and loader are modified to increase stiffness. It is verified that considerable amount of vibration are reduced by the structural modification.

Numerical Simulation of tire Traction on Various Road Conditions

Abstract The tire is the only point of contact between the car and the road and the traction is drastically changed by the road condition. Since the critical functions performed by the tire are determined by a tiny contact interface, the numerical simulation has been pursued to analyze the tire traction on various road conditions. The numerical simulation of tire traction on various road conditions such as ice, snow, water and soil are a very challenging problem, because these involve fluid-structure interaction, tire-road contact analysis and difficulty of tire pattern modeling. In this paper, the study on the numerical simulation of tire traction on various road conditions is reviewed. The tire is analyzed by FEM with Lagrangian formulation and the interfacial material is analyzed by FVM with Eulerian formulation. Since the tire and the interfacial material are modeled separately and their coupling is automatically computed by the coupling element, the tire-interfacial material interaction of the complex geometry, such as the tire with the tread pattern, can be analyzed practically. Since the prediction of tire traction is verified to be in good agreement with experiment, this technology has been started applying the development of tire pattern design. This tool will be one of the key technologies to shorten the period of development. Lastly, future works for this simulation technology are proposed.

Simulation and validation of the ply steer residual aligning torque induced by the tyre tread pattern

This paper describes the simulation procedure of a ply steer residual aligning torque (PRAT) using a stationary global rolling finite-element method (FEM) tyre model combined with a detailed local FEM tread pattern model. The simulated results of the PRAT for eight tread pattern variants are compared with measured values of experimental tyres and do show a high correlation. Additionally, simulated local contact stress distributions of the tread blocks on a rolling tyre show a high degree of similarity compared with measured distributions generated with a specific in-house test drum. Finally, the local contact stresses are mechanically interpreted to obtain a basic understanding of how the PRAT is generated by the tread pattern. The application of the prescribed simulation procedure to realistic serial patterns is planned for the future. Thus tyre body and pattern PRAT effects can be balanced and the car manufacturers’ requirements will be met in an early stage of product development.

A TIRE-MARK IDENTIFICATION SCHEME FOR SUSPECTED VEHICLE DETECTION IN HIT AND RUN ACCIDENT

This study employs Visual dBASE to establish a systematic tire-marks matching database to increase the correctness and efficiency of tire-marks identification executed by investigators at accident scene. The database includes tire manufactures, vehicle type/model, and tire specifications. In addition, it encompasses a tire-marks matching function. It can be more conveniently used to identify the tire pattern and catch tire-treads by inputting the actual widths of light and heavy streaks on the tire-marks. From this systematic system, we can find out the probably involved tire size and vehicle geometric properties and infer from them with the front/rear track and wheelbase to determine the tire-marks' belonging. In its empirical case validation, this system shows that it does increase the operational effectiveness of tire-marks identification and reduce the scope of investigation, especially in hit and run accidents. Furthermore, it does improve the quality of accident investigation and identification.

Surface Shape Optimization of Tire Pattern by Optimality Criteria

Abstract A new optimization procedure to design the surface shape of tire patterns is proposed in which the optimality criteria is combined with finite element method. The effectiveness of this new procedure to control tread-element contact pressure distribution was verified by building and testing the rubber block samples. The objective function was the pressure uniformity on the block and the constraint was to keep the contact area in the optimization process. The shape of the optimized surface was round at the edges and concave at the center where the pressure was large in the flat surface block. The pressure of the block with the optimized surface became uniform and the friction coefficient increased 10% on dry compared with the flat surface block. Furthermore, this procedure was applied to complicated block shapes such as tire patterns and it was verified that the optimized surface effectively improved vehicle handling, riding comfort and irregular wear.

Hydroplaning Analysis by FEM and FVM: Effect of Tire Rolling and Tire Pattern on Hydroplaning

Abstract We established the new numerical procedure for hydroplaning. We considered the following three important factors; fluid/structure interaction, tire rolling, and practical tread pattern. The tire was analyzed by the finite element method with Lagrangian formulation, and the fluid was analyzed by the finite volume method with Eulerian formulation. Since the tire and the fluid can be modeled separately and their coupling is computed automatically, the fluid/structure interaction of the complex geometry, such as the tire with the tread pattern, can be analyzed. Since we focused the aim of the simulation on dynamic hydroplaning with thick water films, we ignored the effect of fluid viscosity. We verified the predictability of the hydroplaning simulation in the different parameters such as the water flow, the velocity dependence of hydroplaning, and the effect of the tread pattern on hydroplaning. These parameters could be predicted qualitatively. We also developed the procedure of the global-local analysis to apply the hydroplaning simulation to a practical tire tread pattern design, and we found that the sloped block tip is effective in improving hydroplaning performance.