Being able to estimate tire/rubber friction is very important to tire engineers, materials developers, and pavement engineers. This is because of the need for estimating forces generated at the contact, optimizing tire and vehicle performance, and estimating tire wear. Efficient models for contact area and interfacial separation are key for accurate prediction of friction coefficient. Based on the contact mechanics and surface roughness, various models were developed that can predict real area of contact and penetration depth/interfacial separation. In the present work, we intend to compare the analytical contact mechanics models using experimental results and numerical analysis. Nano-indentation experiments are performed on the rubber compound to obtain penetration depth data. A finite element model of a rubber block in contact with a rough surface was developed and validated using the nano-indentation experimental data. Results for different operating conditions obtained from the developed finite element model are compared with analytical model results, and further model improvements are discussed.
{"title":"Comparison of Analytical Model for Contact Mechanics Parameters with Numerical Analysis and Experimental Results","authors":"Sunish Vadakkeveetil, A. Nouri, S. Taheri","doi":"10.2346/TIRE.19.180198","DOIUrl":"https://doi.org/10.2346/TIRE.19.180198","url":null,"abstract":"\u0000 Being able to estimate tire/rubber friction is very important to tire engineers, materials developers, and pavement engineers. This is because of the need for estimating forces generated at the contact, optimizing tire and vehicle performance, and estimating tire wear. Efficient models for contact area and interfacial separation are key for accurate prediction of friction coefficient. Based on the contact mechanics and surface roughness, various models were developed that can predict real area of contact and penetration depth/interfacial separation. In the present work, we intend to compare the analytical contact mechanics models using experimental results and numerical analysis. Nano-indentation experiments are performed on the rubber compound to obtain penetration depth data. A finite element model of a rubber block in contact with a rough surface was developed and validated using the nano-indentation experimental data. Results for different operating conditions obtained from the developed finite element model are compared with analytical model results, and further model improvements are discussed.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46171570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The dynamic characteristics of a tire are studied by simulating its rolling over a cleat and observing the effect on in-plane rigid belt vibration modes. Three modeling approaches are used to understand various tire design parameters affecting the tire dynamics relevant for vehicle ride performance. First, a simplified three-degree-of-freedom rigid ring model is used for fundamental understanding of these modes. Next, a detailed finite element model accounting for component compliances is used for studying the sensitivity of the modes to most common design parameter variations employed in tire development. Finally, to study these tire design changes in operation, vehicle simulations using CarSim and FTire models are performed. FTire model parameters corresponding to tire design parameters are adjusted accordingly. Observations are reported of the effects of tire design parameters on cleat responses and on correlation of results between finite element and FTire models.
{"title":"Understanding Tire Dynamic Characteristics for Vehicle Dynamics Ride Using Simulation Methods","authors":"Y. Siramdasu, Kejing Li, R. Wheeler","doi":"10.2346/TIRE.19.180196","DOIUrl":"https://doi.org/10.2346/TIRE.19.180196","url":null,"abstract":"\u0000 The dynamic characteristics of a tire are studied by simulating its rolling over a cleat and observing the effect on in-plane rigid belt vibration modes. Three modeling approaches are used to understand various tire design parameters affecting the tire dynamics relevant for vehicle ride performance. First, a simplified three-degree-of-freedom rigid ring model is used for fundamental understanding of these modes. Next, a detailed finite element model accounting for component compliances is used for studying the sensitivity of the modes to most common design parameter variations employed in tire development. Finally, to study these tire design changes in operation, vehicle simulations using CarSim and FTire models are performed. FTire model parameters corresponding to tire design parameters are adjusted accordingly. Observations are reported of the effects of tire design parameters on cleat responses and on correlation of results between finite element and FTire models.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48574450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Indirect tire pressure monitoring systems (ITPMSs) have been an active area of research for the past 2 decades. Researchers worldwide have strived to develop estimation techniques for the detection of the change in tire pressure by using the vibration information present in the speed signal. Different groups have used a torsional vibration model for the tire, owing to its torsional stiffness and rotational moment of inertia. The standard antilock braking system (ABS) speed sensor signal is analyzed for these vibrations. Different estimation algorithms try to detect the change in this vibration frequency, which indicates the change in the torsional stiffness of the tire as a result of variation in the pressure. Tire vibrations have been studied in great detail for the past 5 decades, and there are various models of tire vibrations available in the literature. These models range from physics-based analytical models to finite element models (FEMs). Analytical models take benefit from the mathematics developed for rotating elastic thin shells and plates, whereas FEMs use simulation tools to develop vibration models of the tire. A detailed literature survey of ITPMSs and tire vibration models reveals that there is no correlation between the vibrations detected in the speed signal and the vibrations predicted in the tire vibration models. Researchers have developed tire vibration models that do not take into consideration the effects of vibrations on the speed signal; although, to the best of our knowledge, signal processing and estimation experts who have developed methods for ITPMSs have not validated the true source of observed vibrations in the speed signal and could not present a viable theoretical explanation. In this review, a comprehensive study of the ITPMS techniques and tire vibration models is presented, with an aim to find a correlation between them. The review begins with a brief introduction to the topic followed by state of the art, then a detailed review of ITPMSs and the methods for their realizations in the automotive industry. Finally, tire vibration models are presented in detail, and possible links between vibration models and ITPMS vibrations are sorted.
{"title":"Technical Review: Indirect Tire Pressure Monitoring Systems and Tire Vibrations","authors":"A. Muhammad","doi":"10.2346/TIRE.18.460403","DOIUrl":"https://doi.org/10.2346/TIRE.18.460403","url":null,"abstract":"\u0000 Indirect tire pressure monitoring systems (ITPMSs) have been an active area of research for the past 2 decades. Researchers worldwide have strived to develop estimation techniques for the detection of the change in tire pressure by using the vibration information present in the speed signal. Different groups have used a torsional vibration model for the tire, owing to its torsional stiffness and rotational moment of inertia. The standard antilock braking system (ABS) speed sensor signal is analyzed for these vibrations. Different estimation algorithms try to detect the change in this vibration frequency, which indicates the change in the torsional stiffness of the tire as a result of variation in the pressure.\u0000 Tire vibrations have been studied in great detail for the past 5 decades, and there are various models of tire vibrations available in the literature. These models range from physics-based analytical models to finite element models (FEMs). Analytical models take benefit from the mathematics developed for rotating elastic thin shells and plates, whereas FEMs use simulation tools to develop vibration models of the tire.\u0000 A detailed literature survey of ITPMSs and tire vibration models reveals that there is no correlation between the vibrations detected in the speed signal and the vibrations predicted in the tire vibration models. Researchers have developed tire vibration models that do not take into consideration the effects of vibrations on the speed signal; although, to the best of our knowledge, signal processing and estimation experts who have developed methods for ITPMSs have not validated the true source of observed vibrations in the speed signal and could not present a viable theoretical explanation.\u0000 In this review, a comprehensive study of the ITPMS techniques and tire vibration models is presented, with an aim to find a correlation between them. The review begins with a brief introduction to the topic followed by state of the art, then a detailed review of ITPMSs and the methods for their realizations in the automotive industry. Finally, tire vibration models are presented in detail, and possible links between vibration models and ITPMS vibrations are sorted.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45245102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Sagar, D. Zheng, A. Suwannachit, M. Brinkmeier, Kristin Fietz, Carsten Hahn
It is widely known that filler-reinforced rubber material in tires shows a very complicated material behavior when subjected to cyclic loadings. One of the most interesting effects for rolling tires is the nonlinear rate-dependent behavior, which is implicitly linked to the amplitude dependency of dynamic stiffness (Payne effect) at a given frequency and temperature. This effect, however, cannot be described by a conventional linear viscoelastic constitutive law, e.g., the Prony series model. Several nonlinear viscoelastic material models have been proposed in the last decades. Among others, Lapczyk et al. (Lapczyk, I., Hurtado, J. A., and Govindarajan, S. M., “A Parallel Rheological Framework for Modeling Elastomers and Polymers,” 182nd Technical Meeting of the Rubber Division of the American Chemical Society, Cincinnati, Ohio, October 2012) recently proposed a quite general framework for the class of nonlinear viscoelasticity, called parallel rheological framework (PRF), which is followed by Abaqus. The model has an open option for different types of viscoelastic creep laws. In spite of the very attractive nonlinear rate-dependency, the identification of material parameters becomes a very challenging task, especially when a wide frequency and amplitude range is of interest. This contribution points out that the creep law is numerically sound if it can be degenerated to the linear viscoelastic model at a very small strain amplitude, which also significantly simplifies model calibration. More precisely, the ratio between viscoelastic stress and strain rate has to converge to a certain value, i.e., the viscosity in a linear viscoelastic case. The creep laws implemented in Abaqus are discussed in detail here, with a focus on their fitting capability. The conclusion of the investigation consequently gives us a guideline to develop a new creep law in PRF. Here, one creep law from Abaqus that meets the requirements of our guideline has been selected. A fairly good fit of the model is shown by the comparison of the simulated complex modulus in a wide frequency and amplitude range with experimental results.
众所周知，轮胎用填充增强橡胶材料在循环荷载作用下表现出非常复杂的材料性能。滚动轮胎最有趣的影响之一是非线性速率依赖行为，这与给定频率和温度下动态刚度的振幅依赖(佩恩效应)隐含地联系在一起。然而，这种效应不能用传统的线性粘弹性本构律来描述，例如，proony系列模型。在过去的几十年里，人们提出了几种非线性粘弹性材料模型。其中，Lapczyk等人(Lapczyk, I.， Hurtado, J. A.，和Govindarajan, S. M.，“模拟弹性体和聚合物的平行流变框架”，美国化学学会橡胶分会第182届技术会议，辛辛那提，俄亥俄州，2012年10月)最近为非线性粘弹性类提出了一个相当通用的框架，称为平行流变框架(PRF)，随后是Abaqus。该模型对不同类型的粘弹性蠕变规律有一个开放的选择。尽管材料参数的非线性速率依赖性非常有吸引力，但材料参数的识别成为一项非常具有挑战性的任务，特别是当对宽频率和幅值范围感兴趣时。这一贡献指出，如果蠕变规律可以在很小的应变幅下退化为线性粘弹性模型，那么它在数值上是合理的，这也大大简化了模型校准。更准确地说，粘弹性应力与应变率之比必须收敛于某一值，即线性粘弹性情况下的粘度。本文详细讨论了在Abaqus中实现的蠕变规律，重点讨论了它们的拟合能力。研究结果为建立新的PRF蠕变规律提供了指导。在这里，从Abaqus中选择了一个符合我们指南要求的蠕变律。在较宽的频率和幅度范围内，模拟的复模量与实验结果的比较表明，该模型具有较好的拟合性。
{"title":"On the Development of Creep Laws for Rubber in the Parallel Rheological Framework","authors":"G. Sagar, D. Zheng, A. Suwannachit, M. Brinkmeier, Kristin Fietz, Carsten Hahn","doi":"10.2346/TIRE.18.470104","DOIUrl":"https://doi.org/10.2346/TIRE.18.470104","url":null,"abstract":"\u0000 It is widely known that filler-reinforced rubber material in tires shows a very complicated material behavior when subjected to cyclic loadings. One of the most interesting effects for rolling tires is the nonlinear rate-dependent behavior, which is implicitly linked to the amplitude dependency of dynamic stiffness (Payne effect) at a given frequency and temperature. This effect, however, cannot be described by a conventional linear viscoelastic constitutive law, e.g., the Prony series model. Several nonlinear viscoelastic material models have been proposed in the last decades. Among others, Lapczyk et al. (Lapczyk, I., Hurtado, J. A., and Govindarajan, S. M., “A Parallel Rheological Framework for Modeling Elastomers and Polymers,” 182nd Technical Meeting of the Rubber Division of the American Chemical Society, Cincinnati, Ohio, October 2012) recently proposed a quite general framework for the class of nonlinear viscoelasticity, called parallel rheological framework (PRF), which is followed by Abaqus. The model has an open option for different types of viscoelastic creep laws. In spite of the very attractive nonlinear rate-dependency, the identification of material parameters becomes a very challenging task, especially when a wide frequency and amplitude range is of interest.\u0000 This contribution points out that the creep law is numerically sound if it can be degenerated to the linear viscoelastic model at a very small strain amplitude, which also significantly simplifies model calibration. More precisely, the ratio between viscoelastic stress and strain rate has to converge to a certain value, i.e., the viscosity in a linear viscoelastic case. The creep laws implemented in Abaqus are discussed in detail here, with a focus on their fitting capability. The conclusion of the investigation consequently gives us a guideline to develop a new creep law in PRF. Here, one creep law from Abaqus that meets the requirements of our guideline has been selected. A fairly good fit of the model is shown by the comparison of the simulated complex modulus in a wide frequency and amplitude range with experimental results.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41834266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Since tires generate the control forces required for the operation of a vehicle, the tire force and moment (F&M) characteristics have to be designed such that the vehicle can easily be kept under driver control under many driving conditions. However, the relationship between F&M characteristics and vehicle handling performance is not well understood for many driving maneuvers. A better understanding of this relationship would thus provide insight into how to improve the matching between tires and vehicles for increased vehicle stability. Building a large number of tires with different characteristics would be too expensive and time consuming, so an investigation using simulations is preferred. However, one problem with simulations is that handling performance cannot be evaluated by a professional driver (subjective metrics), unlike in outdoor tests. A way of evaluating handling performance in simulation through objective metrics is therefore necessary. In this study, the focus is on vehicle handling performance during simultaneous cornering and braking. Desirable F&M metrics were identified using the following process: Handling simulations were validated using instrumented vehicle measurements of handling behavior at outdoor test facilities. An objective handling metric (peak body slip angle) was identified that has high correlation with professional driver ratings (subjective metric) of combined slip handling performance. The objective metric could therefore be used with simulations to predict the professional driver rating. Many virtual tires were generated by changing F&M characteristics of Pacejka tire models. These virtual tires were used in simulations of combined slip handling maneuvers and evaluated for performance using the objective handling metric. By identifying which changes to F&M metrics had high correlation to changes in handling performance, the primary influencing characteristics were determined. These results were also confirmed by looking at the correlation between F&M metrics of actual tires and their subjective ratings.
{"title":"Identification of Tire Force and Moment (F&M) Characteristics That Improve Combined Slip Handling Performance","authors":"T. Wei, H. Dorfi","doi":"10.2346/TIRE.19.160109","DOIUrl":"https://doi.org/10.2346/TIRE.19.160109","url":null,"abstract":"\u0000 Since tires generate the control forces required for the operation of a vehicle, the tire force and moment (F&M) characteristics have to be designed such that the vehicle can easily be kept under driver control under many driving conditions. However, the relationship between F&M characteristics and vehicle handling performance is not well understood for many driving maneuvers. A better understanding of this relationship would thus provide insight into how to improve the matching between tires and vehicles for increased vehicle stability. Building a large number of tires with different characteristics would be too expensive and time consuming, so an investigation using simulations is preferred. However, one problem with simulations is that handling performance cannot be evaluated by a professional driver (subjective metrics), unlike in outdoor tests. A way of evaluating handling performance in simulation through objective metrics is therefore necessary. In this study, the focus is on vehicle handling performance during simultaneous cornering and braking. Desirable F&M metrics were identified using the following process: Handling simulations were validated using instrumented vehicle measurements of handling behavior at outdoor test facilities. An objective handling metric (peak body slip angle) was identified that has high correlation with professional driver ratings (subjective metric) of combined slip handling performance. The objective metric could therefore be used with simulations to predict the professional driver rating. Many virtual tires were generated by changing F&M characteristics of Pacejka tire models. These virtual tires were used in simulations of combined slip handling maneuvers and evaluated for performance using the objective handling metric. By identifying which changes to F&M metrics had high correlation to changes in handling performance, the primary influencing characteristics were determined. These results were also confirmed by looking at the correlation between F&M metrics of actual tires and their subjective ratings.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47594290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rolling resistance defined as energy loss per unit distance is well accepted by the tire science community. It is commonly believed that the dominant part of energy loss into heat is caused by the viscoelasticity of rubber compounds for a free-rolling tire. To calculate the rolling loss (hysteretic loss) into heat, a method based on tire forces and moments has been developed to ease required measurements in a lab or field. This paper points out that, by this method, the obtained energy loss is not entirely converted into heat because a portion of the consumed power is used to compensate mechanical work. Moreover, that part of power cannot be separated out by tire forces and moments–based experimental methods. The researchers and engineers have mistakenly ignored this point for a long time. The finding was demonstrated by a comparative analysis of a rigid, pure elastic, and viscoelastic rolling body. This research mathematically proved that rolling loss into heat is not resolvable in terms of tire forces and moments with their associated velocities. The finite element model of a free-rolling tire was further exercised to justify the concept. These findings prompt revisiting rolling resistance in a new way from the energy perspective. Moreover, an extended definition of rolling resistance is proposed and backward compatible with its traditional definition as a resistive force.
{"title":"Rolling Resistance Revisited","authors":"Yi Li, R. West","doi":"10.2346/TIRE.19.150089","DOIUrl":"https://doi.org/10.2346/TIRE.19.150089","url":null,"abstract":"\u0000 Rolling resistance defined as energy loss per unit distance is well accepted by the tire science community. It is commonly believed that the dominant part of energy loss into heat is caused by the viscoelasticity of rubber compounds for a free-rolling tire. To calculate the rolling loss (hysteretic loss) into heat, a method based on tire forces and moments has been developed to ease required measurements in a lab or field. This paper points out that, by this method, the obtained energy loss is not entirely converted into heat because a portion of the consumed power is used to compensate mechanical work. Moreover, that part of power cannot be separated out by tire forces and moments–based experimental methods. The researchers and engineers have mistakenly ignored this point for a long time. The finding was demonstrated by a comparative analysis of a rigid, pure elastic, and viscoelastic rolling body. This research mathematically proved that rolling loss into heat is not resolvable in terms of tire forces and moments with their associated velocities. The finite element model of a free-rolling tire was further exercised to justify the concept. These findings prompt revisiting rolling resistance in a new way from the energy perspective. Moreover, an extended definition of rolling resistance is proposed and backward compatible with its traditional definition as a resistive force.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43866004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
William V Mars, Yintao Wei, Wang Hao, Mark A. Bauman
Tire developers are responsible for designing against the possibility of crack development in each of the various components of a tire. The task requires knowledge of the fatigue behavior of each compound in the tire, as well as adequate accounting for the multiaxial stresses carried by tire materials. The analysis is illustrated here using the Endurica CL fatigue solver for the case of a 1200R20 TBR tire operating at 837 kPa under loads ranging from 66 to 170% of rated load. The fatigue behavior of the tire's materials is described from a fracture mechanical viewpoint, with care taken to specify each of the several phenomena (crack growth rate, crack precursor size, strain crystallization, fatigue threshold) that govern. The analysis of crack development is made by considering how many cycles are required to grow cracks of various potential orientations at each element of the model. The most critical plane is then identified as the plane with the shortest fatigue life. We consider each component of the tire and show that where cracks develop from precursors intrinsic to the rubber compound (sidewall, tread grooves, innerliner) the critical plane analysis provides a comprehensive view of the failure mechanics. For cases where a crack develops near a stress singularity (i.e., belt-edge separation), the critical plane analysis remains advantageous for design guidance, particularly relative to analysis approaches based upon scalar invariant theories (i.e., strain energy density) that neglect to account for crack closure effects.
{"title":"Computing Tire Component Durability via Critical Plane Analysis","authors":"William V Mars, Yintao Wei, Wang Hao, Mark A. Bauman","doi":"10.2346/TIRE.19.150090","DOIUrl":"https://doi.org/10.2346/TIRE.19.150090","url":null,"abstract":"\u0000 Tire developers are responsible for designing against the possibility of crack development in each of the various components of a tire. The task requires knowledge of the fatigue behavior of each compound in the tire, as well as adequate accounting for the multiaxial stresses carried by tire materials. The analysis is illustrated here using the Endurica CL fatigue solver for the case of a 1200R20 TBR tire operating at 837 kPa under loads ranging from 66 to 170% of rated load. The fatigue behavior of the tire's materials is described from a fracture mechanical viewpoint, with care taken to specify each of the several phenomena (crack growth rate, crack precursor size, strain crystallization, fatigue threshold) that govern. The analysis of crack development is made by considering how many cycles are required to grow cracks of various potential orientations at each element of the model. The most critical plane is then identified as the plane with the shortest fatigue life. We consider each component of the tire and show that where cracks develop from precursors intrinsic to the rubber compound (sidewall, tread grooves, innerliner) the critical plane analysis provides a comprehensive view of the failure mechanics. For cases where a crack develops near a stress singularity (i.e., belt-edge separation), the critical plane analysis remains advantageous for design guidance, particularly relative to analysis approaches based upon scalar invariant theories (i.e., strain energy density) that neglect to account for crack closure effects.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44500286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tires of passenger cars and other special tires are made of rubber compounds and reinforcing cords of different type to form a composite with distinct mechanical and thermal properties. One of the major load cases is the steady state rolling operation during the tire's service. In this contribution, attention is paid to the strain and force state as well as the temperature distribution in the carcass cord layer of a steady state rolling tire. A simple benchmark tire geometry is considered, which is made of one rubber compound, one carcass cord layer (textile), and two belt cord layers (steel). From the given geometry, two tire designs are derived by using two distinct types of reinforcing cords (polyester and rayon) for the carcass cord layer. Subsequently, the two tire designs are subjected to three load cases with different inner pressure, vertical force, and translational velocity. The strain and the force state as well as the temperature distribution in the cords are computed via a thermomechanically coupled finite element simulation approach for each tire design and load case. To realistically capture the thermomechanical behavior of the cords, a temperature- and deformation-dependent nonlinear elastic cord model is proposed. The cord model parameters can be directly derived from data of cord tensile tests at different temperatures. Finally, cord design parameters (minimum and maximum strains and forces in the cords, maximum strain and force range per cycle, and maximum cord temperature) are summarized and compared. Additionally, the global vertical stiffness and the rolling resistance for each tire design are addressed.
{"title":"Finite Element Based Analysis of Reinforcing Cords in Rolling Tires: Influence of Mechanical and Thermal Cord Properties on Tire Response","authors":"R. Behnke, M. Kaliske","doi":"10.2346/TIRE.18.4604010","DOIUrl":"https://doi.org/10.2346/TIRE.18.4604010","url":null,"abstract":"\u0000 Tires of passenger cars and other special tires are made of rubber compounds and reinforcing cords of different type to form a composite with distinct mechanical and thermal properties. One of the major load cases is the steady state rolling operation during the tire's service.\u0000 In this contribution, attention is paid to the strain and force state as well as the temperature distribution in the carcass cord layer of a steady state rolling tire. A simple benchmark tire geometry is considered, which is made of one rubber compound, one carcass cord layer (textile), and two belt cord layers (steel). From the given geometry, two tire designs are derived by using two distinct types of reinforcing cords (polyester and rayon) for the carcass cord layer. Subsequently, the two tire designs are subjected to three load cases with different inner pressure, vertical force, and translational velocity. The strain and the force state as well as the temperature distribution in the cords are computed via a thermomechanically coupled finite element simulation approach for each tire design and load case. To realistically capture the thermomechanical behavior of the cords, a temperature- and deformation-dependent nonlinear elastic cord model is proposed. The cord model parameters can be directly derived from data of cord tensile tests at different temperatures. Finally, cord design parameters (minimum and maximum strains and forces in the cords, maximum strain and force range per cycle, and maximum cord temperature) are summarized and compared. Additionally, the global vertical stiffness and the rolling resistance for each tire design are addressed.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2018-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42002773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The wide-base tire is a relatively new design that originated to replace dual tires because of its potential for improved performance. However, during the construction process, the wide-base tire is more likely to experience tread deformation and uneven stress distribution. The goal of this study is to incorporate numeric techniques for the construction and design optimization of a wide-base, heavy vehicle, pneumatic tire. First, four conditions of the tire (385/55R22.5)–building process, including gluing of components on the main drum, gluing of components on the auxiliary drum, green tire, and finalizing the capsule vulcanizing machine, were simulated using finite element analysis. Second, to solve the difference in the tire's (435/50R19.5) material distribution between the real manufactured structure and the theoretical structure, the curved surface drum-building method and the parameters of the curved surface drum were determined by tire construction simulation. In this article, we present the method for collecting tire material, the measurement process, the analysis method, some general results, and statistics on the wide-base tire. Finally, validation of results of the simulation and measurement are given.
{"title":"Wide-Base Tire-Building Process and Design Optimization Using Finite Element Analysis","authors":"Haichao Zhou, Guolin Wang, Wang Yuming","doi":"10.2346/TIRE.18.460405","DOIUrl":"https://doi.org/10.2346/TIRE.18.460405","url":null,"abstract":"\u0000 The wide-base tire is a relatively new design that originated to replace dual tires because of its potential for improved performance. However, during the construction process, the wide-base tire is more likely to experience tread deformation and uneven stress distribution. The goal of this study is to incorporate numeric techniques for the construction and design optimization of a wide-base, heavy vehicle, pneumatic tire. First, four conditions of the tire (385/55R22.5)–building process, including gluing of components on the main drum, gluing of components on the auxiliary drum, green tire, and finalizing the capsule vulcanizing machine, were simulated using finite element analysis. Second, to solve the difference in the tire's (435/50R19.5) material distribution between the real manufactured structure and the theoretical structure, the curved surface drum-building method and the parameters of the curved surface drum were determined by tire construction simulation. In this article, we present the method for collecting tire material, the measurement process, the analysis method, some general results, and statistics on the wide-base tire. Finally, validation of results of the simulation and measurement are given.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2018-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41367209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Riehm, M. Greiner, Karl-Ludwig Bückle, H. Unrau, F. Gauterin
To improve and better understand the tire wet grip mechanism, it is essential to perform test bench measurements under wet conditions. On both public streets and the track surfaces of the internal drum test bench of the Karlsruhe Institute of Technology (KIT), a drop in the friction level of the track surface can be observed with an increasing number of wet measurements. For this purpose, a new measuring device was developed and built: the continuous friction monitoring system (CFM-System). The measuring principle is a continuously braked standard test tire, whereby a longitudinal friction coefficient is determined. To establish a suitable measuring method using the CFM-System, a basic understanding of the longitudinal behavior of this standard test tire was achieved. For this purpose, μ-slip characteristics were determined to investigate the friction behavior of this tire under different slip conditions. Furthermore, the influence of wheel load and driving speed were examined and analyzed. Based on these findings, an adequate test method was derived. The investigations presented in this article show a good relation between the results of the CFM-System and the results obtained from measurements using the standard reference test tire (SRTT). The results show that this new CFM-System is suitable for monitoring the grip level of the track surface on the internal drum test bench when performing wet grip measurements. It is assumed that the results can be directly transferred to the real road or to proving grounds because real track surfaces are used on the test bench.
为了改进和更好地了解轮胎湿抓地力机理，有必要在潮湿条件下进行试验台测量。在公共街道和卡尔斯鲁厄理工学院(Karlsruhe Institute of Technology, KIT)内部鼓式试验台的轨道表面上，随着湿法测量次数的增加，可以观察到轨道表面摩擦水平的下降。为此，研制了一种新的测量装置:连续摩擦监测系统(CFM-System)。测量原理是连续制动的标准试验轮胎，由此确定纵向摩擦系数。为了使用cfm系统建立合适的测量方法，对该标准试验轮胎的纵向行为有了基本的了解。为此，测定了该轮胎在不同滑移条件下的μ滑移特性，研究了其摩擦性能。此外，还对车轮载荷和行驶速度的影响进行了检验和分析。基于这些发现，推导出一种适当的测试方法。本文提出的研究表明cfm系统的结果与使用标准参考测试轮胎(SRTT)的测量结果之间存在良好的关系。结果表明，该cfm系统适用于湿抓地力测量时，在内鼓测试台上监测轨道表面的抓地力水平。由于试验台使用的是真实的赛道表面，因此假设试验结果可以直接转移到实际道路或试验场。
{"title":"A Measuring System for Continuous Friction Monitoring on Wet Track Surfaces","authors":"P. Riehm, M. Greiner, Karl-Ludwig Bückle, H. Unrau, F. Gauterin","doi":"10.2346/TIRE.18.460401","DOIUrl":"https://doi.org/10.2346/TIRE.18.460401","url":null,"abstract":"\u0000 To improve and better understand the tire wet grip mechanism, it is essential to perform test bench measurements under wet conditions. On both public streets and the track surfaces of the internal drum test bench of the Karlsruhe Institute of Technology (KIT), a drop in the friction level of the track surface can be observed with an increasing number of wet measurements. For this purpose, a new measuring device was developed and built: the continuous friction monitoring system (CFM-System). The measuring principle is a continuously braked standard test tire, whereby a longitudinal friction coefficient is determined. To establish a suitable measuring method using the CFM-System, a basic understanding of the longitudinal behavior of this standard test tire was achieved. For this purpose, μ-slip characteristics were determined to investigate the friction behavior of this tire under different slip conditions. Furthermore, the influence of wheel load and driving speed were examined and analyzed. Based on these findings, an adequate test method was derived. The investigations presented in this article show a good relation between the results of the CFM-System and the results obtained from measurements using the standard reference test tire (SRTT). The results show that this new CFM-System is suitable for monitoring the grip level of the track surface on the internal drum test bench when performing wet grip measurements. It is assumed that the results can be directly transferred to the real road or to proving grounds because real track surfaces are used on the test bench.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2018-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44729730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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