Jonas Alexander Heidelberger, Matthias Wangenheim, Klaus Wiese, Burkhard Wies, Christoph Bederna
ABSTRACT It is known that different weather conditions require a specific design to take into account the main mechanisms acting between the tire tread block and the road surface. When developing all-season tires, additional research is necessary to find the best solution considering various road conditions. This paper analyzes the influence of the inclination angle of tire tread blocks and the tire tread blocks siping design on different surfaces on the friction forces in lateral and longitudinal directions. The tests were conducted on the hybrid test rig Realistic Pattern Testing in Lab at the Institute for Dynamics and Vibration Research of the Leibniz University of Hanover with different single tread blocks. Tire tread blocks with different numbers of sipes were rotated with an angle between 0° to 90° in 15° increments. To simulate different road conditions, artificially produced ice and snow tracks and real road wet and dry asphalt were used. For a better understanding of the mechanisms, high-speed images of the same samples sliding over a wet glass track were taken from below. On the one hand, the measurement results and videos help to understand the influence of the inclination angle of a tread block sample on the friction process and show the different friction mechanisms on different surfaces and resulting forces in the two directions. On the other hand, the results show clear favorites for optimizing performance on individual surfaces.
{"title":"Target Conflict for Force Transmission in Lateral and Longitudinal Direction of Rotated Tread Block Samples on Different Road Surfaces (Dry, Wet, Snow, and Ice)","authors":"Jonas Alexander Heidelberger, Matthias Wangenheim, Klaus Wiese, Burkhard Wies, Christoph Bederna","doi":"10.2346/tst-22-011","DOIUrl":"https://doi.org/10.2346/tst-22-011","url":null,"abstract":"ABSTRACT It is known that different weather conditions require a specific design to take into account the main mechanisms acting between the tire tread block and the road surface. When developing all-season tires, additional research is necessary to find the best solution considering various road conditions. This paper analyzes the influence of the inclination angle of tire tread blocks and the tire tread blocks siping design on different surfaces on the friction forces in lateral and longitudinal directions. The tests were conducted on the hybrid test rig Realistic Pattern Testing in Lab at the Institute for Dynamics and Vibration Research of the Leibniz University of Hanover with different single tread blocks. Tire tread blocks with different numbers of sipes were rotated with an angle between 0° to 90° in 15° increments. To simulate different road conditions, artificially produced ice and snow tracks and real road wet and dry asphalt were used. For a better understanding of the mechanisms, high-speed images of the same samples sliding over a wet glass track were taken from below. On the one hand, the measurement results and videos help to understand the influence of the inclination angle of a tread block sample on the friction process and show the different friction mechanisms on different surfaces and resulting forces in the two directions. On the other hand, the results show clear favorites for optimizing performance on individual surfaces.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136210231","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}
V. K. Bedi, M. Mondal, A. Saha, K. V. N. Rao, P. Ghosh, R. Mukhopadhyay
ABSTRACT Uniformity characteristics of a tire are a direct reflection of the quality of the manufacturing process that produced it. This is realized in the homogeneity of its different stiffnesses and dimensions around the tire. Evidently, this is the most closely monitored aspect for consistency, from the original equipment manufacturers and manufacturers alike, and the requirement for tighter acceptance criteria is ever-increasing. However, the authors endeavor to find the lowest theoretical level for the same, given the intrinsic sources. The current study attempts to establish a framework to investigate the effect of the most pronounced factors individually, their interplay, and how their combined effect can be minimized. The present work on a 185/65R15 passenger car radial tire attempts to determine the effect of variable pitch sequencing as well as splicing and tread runout for a patterned tire on radial force variation (RFV). The study is carried out using finite element simulation for it presents the opportunity to study the individual effects systemically and economically. The study reveals a nearly 20% of the specification limit can be due to tread pattern sequence while the effect of the overlapping components may vary by 10% of the same limit. The study also suggests spotting arrangements to target and avoid. Finally, the authors present a method, captured in a MATLAB program that benefits the tire designer, plant engineer, and quality control manager.
{"title":"Modelling Intrinsic Sources of Nonuniformity and Their Interplay","authors":"V. K. Bedi, M. Mondal, A. Saha, K. V. N. Rao, P. Ghosh, R. Mukhopadhyay","doi":"10.2346/144030","DOIUrl":"https://doi.org/10.2346/144030","url":null,"abstract":"ABSTRACT Uniformity characteristics of a tire are a direct reflection of the quality of the manufacturing process that produced it. This is realized in the homogeneity of its different stiffnesses and dimensions around the tire. Evidently, this is the most closely monitored aspect for consistency, from the original equipment manufacturers and manufacturers alike, and the requirement for tighter acceptance criteria is ever-increasing. However, the authors endeavor to find the lowest theoretical level for the same, given the intrinsic sources. The current study attempts to establish a framework to investigate the effect of the most pronounced factors individually, their interplay, and how their combined effect can be minimized. The present work on a 185/65R15 passenger car radial tire attempts to determine the effect of variable pitch sequencing as well as splicing and tread runout for a patterned tire on radial force variation (RFV). The study is carried out using finite element simulation for it presents the opportunity to study the individual effects systemically and economically. The study reveals a nearly 20% of the specification limit can be due to tread pattern sequence while the effect of the overlapping components may vary by 10% of the same limit. The study also suggests spotting arrangements to target and avoid. Finally, the authors present a method, captured in a MATLAB program that benefits the tire designer, plant engineer, and quality control manager.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136210683","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}
ABSTRACT Many of the challenging problems in tire dynamics are related to what happens inside the contact patch. Important tire performance attributes such as grip/friction, wear, and noise are all directly related to the contact patch. Calspan and its technology partner Tekscan have developed a novel sensor system that measures the contact patch pressure of the tire as it is rolling at high speed on a flat-belt tire test machine. The measurement results provide detailed insights into the dynamic contact patch pressure (DCPP) in a wide range of realistic and relevant operating conditions on a flat roadway surface. The contact patch behaviors of three tires of similar size and type, but from different manufacturers, were compared. The results highlight how differences in tire design decisions influence the contact patch behavior and in turn the overall tire performance. Additional applications of the DCPP data are presented and discussed.
{"title":"Measurement of Contact Patch Pressure Behaviors in High-Speed Dynamic Conditions","authors":"M. Furlan, M. Strang, M. Gladstone, H. Olsson","doi":"10.2346/789802","DOIUrl":"https://doi.org/10.2346/789802","url":null,"abstract":"ABSTRACT Many of the challenging problems in tire dynamics are related to what happens inside the contact patch. Important tire performance attributes such as grip/friction, wear, and noise are all directly related to the contact patch. Calspan and its technology partner Tekscan have developed a novel sensor system that measures the contact patch pressure of the tire as it is rolling at high speed on a flat-belt tire test machine. The measurement results provide detailed insights into the dynamic contact patch pressure (DCPP) in a wide range of realistic and relevant operating conditions on a flat roadway surface. The contact patch behaviors of three tires of similar size and type, but from different manufacturers, were compared. The results highlight how differences in tire design decisions influence the contact patch behavior and in turn the overall tire performance. Additional applications of the DCPP data are presented and discussed.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135696520","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}
ABSTRACT Parameterization methods for two “commercial tire models—short wavelength intermediate frequency tire (SWIFT) model and flexible ring tire model—are developed around existing testing protocols. As an example, cleat tests are used for estimating belt mass and stiffness and enveloping tests are used for estimating belt bending and contact stiffness parameters in the respective tire models. This is the only way when commercial tire models are parameterized and used mainly by vehicle original equipment manufacturer companies. At present, tire suppliers are stepping up to supply commercial tire models as a part of virtual tire submissions and are virtually simulating standard testing protocols. It is envisioned that with a proper fundamental understanding of commercial tire model parameters and their modeling approaches to capture the respective tire dynamics, we can develop simple finite element (FE) techniques to estimate respective tire model parameters, thereby avoiding the simulation of cleat and other dynamic tests by using FE. With that motivation, previous work has already shown the estimation of belt mass and bending properties from FE part separation technique. In this work, with a fundamental understanding that the front cam and rear cam models in SWIFT are mathematically modeling the curvature of a loaded tire just outside of the footprint, we show that by fitting the tandem model to the loaded FE model deformed co-ordinates length, height, order of cam, and distance between the cams can be estimated easily. This simple loaded FE model-fitting technique is combined with other computationally simple FE static stiffness, footprint, and modal analyses to estimate other SWIFT parameters. Finally, SWIFT models from the above-mentioned FE techniques are developed for several tire designs and validated against enveloping and dynamic in-plane cleat test data. The variations in enveloping and other ride metrics from simulations are inline with testing data.
{"title":"Generation of SWIFT Models Virtually Using FE Analysis: Application to Cleat Simulations","authors":"Yaswanth Siramdasu, Gibin Gil","doi":"10.2346/137595","DOIUrl":"https://doi.org/10.2346/137595","url":null,"abstract":"ABSTRACT Parameterization methods for two “commercial tire models—short wavelength intermediate frequency tire (SWIFT) model and flexible ring tire model—are developed around existing testing protocols. As an example, cleat tests are used for estimating belt mass and stiffness and enveloping tests are used for estimating belt bending and contact stiffness parameters in the respective tire models. This is the only way when commercial tire models are parameterized and used mainly by vehicle original equipment manufacturer companies. At present, tire suppliers are stepping up to supply commercial tire models as a part of virtual tire submissions and are virtually simulating standard testing protocols. It is envisioned that with a proper fundamental understanding of commercial tire model parameters and their modeling approaches to capture the respective tire dynamics, we can develop simple finite element (FE) techniques to estimate respective tire model parameters, thereby avoiding the simulation of cleat and other dynamic tests by using FE. With that motivation, previous work has already shown the estimation of belt mass and bending properties from FE part separation technique. In this work, with a fundamental understanding that the front cam and rear cam models in SWIFT are mathematically modeling the curvature of a loaded tire just outside of the footprint, we show that by fitting the tandem model to the loaded FE model deformed co-ordinates length, height, order of cam, and distance between the cams can be estimated easily. This simple loaded FE model-fitting technique is combined with other computationally simple FE static stiffness, footprint, and modal analyses to estimate other SWIFT parameters. Finally, SWIFT models from the above-mentioned FE techniques are developed for several tire designs and validated against enveloping and dynamic in-plane cleat test data. The variations in enveloping and other ride metrics from simulations are inline with testing data.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135396885","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}
Mahmoud Assaad, Tom Ebbott, Bing Jiang, Gert Rebel
ABSTRACT Cooler running tires with a reduced rolling resistance is a consideration for both tire makers and automotive original equipment manufacturers. To investigate the mechanics of energy loss and temperature rise, a nonlinear viscoelastic model suitable for numerical analysis of rolling tires is developed and demonstrated. The rubber compounds are represented as nonlinear viscoelastic materials with temperature and frequency, strain, and strain history–dependent response. Several applications to different tire designs are provided to demonstrate the impact of this new material constitutive law in improving the quality of the numerical predictions over other methods. One application is a rolling tire model that was used to delineate the tire temperature distribution and the resultant rolling resistance for different three-dimensional tread patterns.
{"title":"Rubber Comprehensive Constitutive Equation and the Prediction of Tire Temperature and Rolling Resistance","authors":"Mahmoud Assaad, Tom Ebbott, Bing Jiang, Gert Rebel","doi":"10.2346/tst-21-012","DOIUrl":"https://doi.org/10.2346/tst-21-012","url":null,"abstract":"ABSTRACT Cooler running tires with a reduced rolling resistance is a consideration for both tire makers and automotive original equipment manufacturers. To investigate the mechanics of energy loss and temperature rise, a nonlinear viscoelastic model suitable for numerical analysis of rolling tires is developed and demonstrated. The rubber compounds are represented as nonlinear viscoelastic materials with temperature and frequency, strain, and strain history–dependent response. Several applications to different tire designs are provided to demonstrate the impact of this new material constitutive law in improving the quality of the numerical predictions over other methods. One application is a rolling tire model that was used to delineate the tire temperature distribution and the resultant rolling resistance for different three-dimensional tread patterns.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":"131 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135857700","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}
ABSTRACT By applying recognized engineering methods, including finite element analysis, the role of impact events on the service life of a tire was studied by varying three factors: speed of impact, treadwear, and angle of impact. The approach combines well-known finite element analysis methods to simulate a tire rolling over an obstacle with the calculation of damage at the tire belt edge imparted by the impact event by using recognized methods of rubber fatigue analysis. An efficient method is developed and used to demonstrate that across a range of impact conditions, some conditions can cause substantial internal damage, whereas other conditions can cause very little damage. The area of investigation is the tire belt edge; thus, although significant internal damage may have occurred, it might not be visually perceptible in the normal operation of a vehicle. In some cases, the nondetectable damage is shown to propagate to a point where the tire loses its structural integrity before reaching its normal operating life defined by treadwear. This study includes the role of mechanical, temperature, and rate effects
{"title":"Predicting Residual Casing Life of a Tire following an Impact Event","authors":"Gobi Gobinath, Thomas Ebbott, Shannon Hughes","doi":"10.2346/tire.23.22003","DOIUrl":"https://doi.org/10.2346/tire.23.22003","url":null,"abstract":"ABSTRACT By applying recognized engineering methods, including finite element analysis, the role of impact events on the service life of a tire was studied by varying three factors: speed of impact, treadwear, and angle of impact. The approach combines well-known finite element analysis methods to simulate a tire rolling over an obstacle with the calculation of damage at the tire belt edge imparted by the impact event by using recognized methods of rubber fatigue analysis. An efficient method is developed and used to demonstrate that across a range of impact conditions, some conditions can cause substantial internal damage, whereas other conditions can cause very little damage. The area of investigation is the tire belt edge; thus, although significant internal damage may have occurred, it might not be visually perceptible in the normal operation of a vehicle. In some cases, the nondetectable damage is shown to propagate to a point where the tire loses its structural integrity before reaching its normal operating life defined by treadwear. This study includes the role of mechanical, temperature, and rate effects","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136178413","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 aircraft tire is the link between the aircraft and the runway and transmits forces and moments within the contact area. During ground maneuvers, the tire is exposed to a wide range of operating conditions. The tires support the weight of the aircraft, they ensure safe rolling during taxiing, and they transfer the required forces to the runway during takeoff and landing. Temperature development during these maneuvers is of great importance because temperature can affect both material stiffness and friction behavior as well as wear characteristics. Heat is generated inside the tire due to energy dissipation caused by the cyclic loading of the tire during rolling. In addition, heat is generated due to friction in the tire–runway contact. Experimental measurements of the temperature distribution in the entire tire are not yet possible. The tire temperatures can only be determined at selected critical spots. Simulation models can help to obtain a better understanding of the overall tire temperature distribution during transient maneuvers. In this work, the transient thermomechanical processes of a rolling aircraft tire, e.g., directly following the touchdown process or during taxiing, are modeled based on a simple physical tire model. An extended brush model is used to simulate the contact forces. The tire temperature is determined via the transient heat conduction equation in radial and circumferential directions. The mechanical and thermal models are coupled via the coefficient of friction and the sliding velocities in contact. The free model parameters are parameterized using experimental data, and the overall model is validated by measurements on the whole tire. The validated thermomechanical tire model is used for simulations or the analysis of different driving maneuvers to get a better understanding of the temperature development in the aircraft tire.
{"title":"Thermomechanical Modeling of Aircraft Tire–Runway Contact for Transient Maneuvers","authors":"S. Kahms, Michael Hindemith, M. Wangenheim","doi":"10.2346/tire.23.22012","DOIUrl":"https://doi.org/10.2346/tire.23.22012","url":null,"abstract":"\u0000 The aircraft tire is the link between the aircraft and the runway and transmits forces and moments within the contact area. During ground maneuvers, the tire is exposed to a wide range of operating conditions. The tires support the weight of the aircraft, they ensure safe rolling during taxiing, and they transfer the required forces to the runway during takeoff and landing. Temperature development during these maneuvers is of great importance because temperature can affect both material stiffness and friction behavior as well as wear characteristics. Heat is generated inside the tire due to energy dissipation caused by the cyclic loading of the tire during rolling. In addition, heat is generated due to friction in the tire–runway contact. Experimental measurements of the temperature distribution in the entire tire are not yet possible. The tire temperatures can only be determined at selected critical spots. Simulation models can help to obtain a better understanding of the overall tire temperature distribution during transient maneuvers. In this work, the transient thermomechanical processes of a rolling aircraft tire, e.g., directly following the touchdown process or during taxiing, are modeled based on a simple physical tire model. An extended brush model is used to simulate the contact forces. The tire temperature is determined via the transient heat conduction equation in radial and circumferential directions. The mechanical and thermal models are coupled via the coefficient of friction and the sliding velocities in contact. The free model parameters are parameterized using experimental data, and the overall model is validated by measurements on the whole tire. The validated thermomechanical tire model is used for simulations or the analysis of different driving maneuvers to get a better understanding of the temperature development in the aircraft tire.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44965803","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}
Dynamic increment in Mars exploration missions necessitates the development of new materials that can satisfy the ever more stringent requirements. Currently, most of the materials used for manufacturing Mars rovers and landers are based on various metal alloys that provide high reliability in the Martian environment. However, the future planned missions, including the first human crew landing on Mars, require the development of new rubber materials that could be used for sealing Mars suits, for tires/tracks, and for damping systems for heavy Mars rovers. This research aims to investigate the properties of butadiene rubber (BR) and butadiene/vinyl-methyl silicone rubber blends (BR/VMQ) filled with various reinforcing fillers: carbon blacks (CBs), silicas, and nanometric calcium carbonate (nano-CaCO3), in order to evaluate their performance from the point of view of Mars' environmental applications. The study revealed that the designed composites exhibit very good low-temperature elasticity, and the addition of 30 phr of high surface area CB (N220) or silica (Ultrasil 9100) results in good mechanical properties of the compounds. The mechanical properties of the BR/VMQ blends depend on the type of reinforcing filler. The addition of the CBs resulted in better mechanical properties, while the incorporation of silicas worsens the mechanical properties of BR/VMQ blends in comparison to their BR counterparts. The high-cis BR grade exhibits a strong tendency to crystallize in the operating temperature range on Mars (crystallization ∼−60 °C, melting ∼−20 °C), and the addition of the fillers nucleates the crystallization, resulting in a higher amount of the crystalline phase. This might be a serious problem for any sealing application of the rubber compounds. For this reason, a non-crystallizable BR grade is recommended for further studies.
{"title":"Tires for Mars Rovers: Reinforcing BR and BR/Vinyl-Methyl Silicone Rubber Compounds with Carbon Black, Nano-CaCO3, or Silica for Good Low-Temperature Dynamic-Mechanical Performance","authors":"R. Anyszka, Lili Jia, A. Blume","doi":"10.2346/tire.23.23003","DOIUrl":"https://doi.org/10.2346/tire.23.23003","url":null,"abstract":"\u0000 Dynamic increment in Mars exploration missions necessitates the development of new materials that can satisfy the ever more stringent requirements. Currently, most of the materials used for manufacturing Mars rovers and landers are based on various metal alloys that provide high reliability in the Martian environment. However, the future planned missions, including the first human crew landing on Mars, require the development of new rubber materials that could be used for sealing Mars suits, for tires/tracks, and for damping systems for heavy Mars rovers. This research aims to investigate the properties of butadiene rubber (BR) and butadiene/vinyl-methyl silicone rubber blends (BR/VMQ) filled with various reinforcing fillers: carbon blacks (CBs), silicas, and nanometric calcium carbonate (nano-CaCO3), in order to evaluate their performance from the point of view of Mars' environmental applications. The study revealed that the designed composites exhibit very good low-temperature elasticity, and the addition of 30 phr of high surface area CB (N220) or silica (Ultrasil 9100) results in good mechanical properties of the compounds. The mechanical properties of the BR/VMQ blends depend on the type of reinforcing filler. The addition of the CBs resulted in better mechanical properties, while the incorporation of silicas worsens the mechanical properties of BR/VMQ blends in comparison to their BR counterparts. The high-cis BR grade exhibits a strong tendency to crystallize in the operating temperature range on Mars (crystallization ∼−60 °C, melting ∼−20 °C), and the addition of the fillers nucleates the crystallization, resulting in a higher amount of the crystalline phase. This might be a serious problem for any sealing application of the rubber compounds. For this reason, a non-crystallizable BR grade is recommended for further studies.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46212897","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}
Ryota Nakanishi, M. Matsubara, Takashi Ishibashi, S. Kawamura, Daiki Tajiri
The influence of tires on vehicle dynamics, as the only automotive component in contact with the road surface, is significant. Mechanical models such as the Fiala model includes tire mechanical properties as parameters and are useful for tire design studies. These models assume a rectangular or trapezoidal tire contact shape, which does not always match the tire contact shape observed when slip angle is applied, leaving room for improvement in accuracy. This study proposes a new semiphysical tire model with an elliptical contact shape, termed the “elliptical contact model.” First, the expressions for the contact shape and contact pressure distributions in the elliptical contact model are formulated. Herein, we consider both the length- and width-direction distributions of the contact pressure in these expressions. Second, the formulation of the lateral shear stress distribution in the contact patch is presented based on the Fiala model, including the belt bending deformation by a lateral force and switching between the lateral shear and dynamic frictional forces. Lateral stresses proportional to the width coordinate are also introduced, enabling the calculation of lateral stresses acting in a direction counteracting each other at the widthwise edge of the tire contact surface. The model is validated by measuring a slick tire at a velocity of 100 km/h with slip angles of 0° and 3° using an Inside Drum Machine with an aluminum road segment with quartz piezoelectric sensors. Consequently, by setting appropriate model parameters, the contact pressure and lateral shear stress distribution results calculated using the model are consistent with experimental results. The accuracy of the proposed model could be further improved by revising the method of setting the static and dynamic friction coefficients.
{"title":"Experimental Validation of Elliptical Contact Patch Tire Model","authors":"Ryota Nakanishi, M. Matsubara, Takashi Ishibashi, S. Kawamura, Daiki Tajiri","doi":"10.2346/tire.23.22008","DOIUrl":"https://doi.org/10.2346/tire.23.22008","url":null,"abstract":"\u0000 The influence of tires on vehicle dynamics, as the only automotive component in contact with the road surface, is significant. Mechanical models such as the Fiala model includes tire mechanical properties as parameters and are useful for tire design studies. These models assume a rectangular or trapezoidal tire contact shape, which does not always match the tire contact shape observed when slip angle is applied, leaving room for improvement in accuracy. This study proposes a new semiphysical tire model with an elliptical contact shape, termed the “elliptical contact model.” First, the expressions for the contact shape and contact pressure distributions in the elliptical contact model are formulated. Herein, we consider both the length- and width-direction distributions of the contact pressure in these expressions. Second, the formulation of the lateral shear stress distribution in the contact patch is presented based on the Fiala model, including the belt bending deformation by a lateral force and switching between the lateral shear and dynamic frictional forces. Lateral stresses proportional to the width coordinate are also introduced, enabling the calculation of lateral stresses acting in a direction counteracting each other at the widthwise edge of the tire contact surface. The model is validated by measuring a slick tire at a velocity of 100 km/h with slip angles of 0° and 3° using an Inside Drum Machine with an aluminum road segment with quartz piezoelectric sensors. Consequently, by setting appropriate model parameters, the contact pressure and lateral shear stress distribution results calculated using the model are consistent with experimental results. The accuracy of the proposed model could be further improved by revising the method of setting the static and dynamic friction coefficients.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":" 21","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41254654","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}
When a tire operates at a side slip level above peak friction, large vibrations in the produced forces and moments are observed. In the lateral direction, these vibrations are typically centered at frequencies close to 50 Hz and significantly affect the force that is produced by the tire. As an example, high dynamics vehicle maneuvers with an electronic stability program control system in the loop can be affected by this behavior. To accurately reproduce the tire response in these operating conditions, it is important to employ a model that can capture this phenomenon. Based on analysis of nonlinear, unstable systems and limit cycle phenomenon, a theory is presented that provides a physical background for the source of vibrations. The theory also gives insight in how the frequency and amplitude of the vibrations are influenced by the tire physical characteristics and the operating conditions. It is found that the most dominant characteristics are the shape of the steady-state force response of the tire around peak friction, the contact patch mass, the carcass damping and stiffness. Simulations with physical models of different complexity levels, as well as with the commercial Simcenter Tire MF-Tyre/MF-Swift tire software model, validate the theory and demonstrate how the vibrations can be reproduced in a simulation environment. The simulation results are compared with tire measurements in different operating conditions, validating the exposed theory and employed models.
{"title":"A Study on Self-Sustained Vibrations of a Tire Operating above Peak Friction","authors":"C. Lugaro, Y. Li, M. Alirezaei","doi":"10.2346/tire.23.22015","DOIUrl":"https://doi.org/10.2346/tire.23.22015","url":null,"abstract":"\u0000 When a tire operates at a side slip level above peak friction, large vibrations in the produced forces and moments are observed. In the lateral direction, these vibrations are typically centered at frequencies close to 50 Hz and significantly affect the force that is produced by the tire. As an example, high dynamics vehicle maneuvers with an electronic stability program control system in the loop can be affected by this behavior. To accurately reproduce the tire response in these operating conditions, it is important to employ a model that can capture this phenomenon.\u0000 Based on analysis of nonlinear, unstable systems and limit cycle phenomenon, a theory is presented that provides a physical background for the source of vibrations. The theory also gives insight in how the frequency and amplitude of the vibrations are influenced by the tire physical characteristics and the operating conditions. It is found that the most dominant characteristics are the shape of the steady-state force response of the tire around peak friction, the contact patch mass, the carcass damping and stiffness. Simulations with physical models of different complexity levels, as well as with the commercial Simcenter Tire MF-Tyre/MF-Swift tire software model, validate the theory and demonstrate how the vibrations can be reproduced in a simulation environment. The simulation results are compared with tire measurements in different operating conditions, validating the exposed theory and employed models.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46193489","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：