Tires with embedded sensors enable them to be active sensing components. Intelligent tires have increased potential in sensing not only the state of the tire itself but the related properties of the road. This Technical Note briefly describes the application of accelerometer-based intelligent tires in sensing the adhesion level and unevenness of the road. A combined tire longitudinal dynamic model is introduced to estimate the tire-road friction from the waveform features of the acceleration signals. Data-driven methods are adopted to directly classify the road unevenness level from the original signals. Primary analyses and experiments verify the proposed method. Road sensing with intelligent tires contributes to the development of active safety control and driving assistance systems.
{"title":"Road Sensing with Intelligent Tires for Driving Assistance Applications","authors":"Tong Zhao, M. Kaliske, Yintao Wei","doi":"10.2346/tire.22.22005","DOIUrl":"https://doi.org/10.2346/tire.22.22005","url":null,"abstract":"\u0000 Tires with embedded sensors enable them to be active sensing components. Intelligent tires have increased potential in sensing not only the state of the tire itself but the related properties of the road. This Technical Note briefly describes the application of accelerometer-based intelligent tires in sensing the adhesion level and unevenness of the road. A combined tire longitudinal dynamic model is introduced to estimate the tire-road friction from the waveform features of the acceleration signals. Data-driven methods are adopted to directly classify the road unevenness level from the original signals. Primary analyses and experiments verify the proposed method. Road sensing with intelligent tires contributes to the development of active safety control and driving assistance systems.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43913195","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}
Dominic Neumann, Mustaba Ahmadi, M. Weinberger, D. Schramm
The virtual design of steering systems requires suitable premises for predicting realistic steering rack forces. This includes the proper tire used for the parking maneuver. It is important to select the tire from a portfolio that generates the highest rack forces at the vehicle, so that the electro-mechanical dimensioning of the steering system can be safeguarded for all tires of a vehicle. To avoid time-consuming and expensive full vehicle measurements, drilling torques of tires are measured on a Flat-Trac to determine the so-called worst-case tire. However, the determined drilling torques do not correlate with the measured rack forces. This work therefore investigates the suitability of a Kinematics & Compliance test rig converted to a tire test rig. First, it is investigated whether the wheel movements from the parking maneuver can be decomposed into their individual elements on the test bench. In addition, reproducibility studies are carried out and three different methods for determining the aligning torque under camber are presented. Furthermore, measurements for static and dynamic friction values, as well as stiffnesses and the contact patch, are integrated into the new measurement procedure. It becomes apparent that temperature and wear level of the tire play a major role in the reproducibility of the measurements. If the measurement procedure described in this paper is followed exactly, the scatter of the drilling torque can be reduced by up to 24% compared to the old procedure. For the dynamic and the static friction values, the scatter is reduced by about 17% and 22%, respectively. Stiffness scatter can be reduced by up to 16%. With the new measurement procedure, the worst-case tire can be reliably determined. The drilling torques correlate with the rack forces and the additional tire characteristics permit finer resolution. After evaluation and interpretation, recommendations for future developments are discussed.
{"title":"Identification of Characteristic Tire Parameters for the Virtual Steering System Design","authors":"Dominic Neumann, Mustaba Ahmadi, M. Weinberger, D. Schramm","doi":"10.2346/tire.22.22002","DOIUrl":"https://doi.org/10.2346/tire.22.22002","url":null,"abstract":"\u0000 The virtual design of steering systems requires suitable premises for predicting realistic steering rack forces. This includes the proper tire used for the parking maneuver. It is important to select the tire from a portfolio that generates the highest rack forces at the vehicle, so that the electro-mechanical dimensioning of the steering system can be safeguarded for all tires of a vehicle. To avoid time-consuming and expensive full vehicle measurements, drilling torques of tires are measured on a Flat-Trac to determine the so-called worst-case tire. However, the determined drilling torques do not correlate with the measured rack forces.\u0000 This work therefore investigates the suitability of a Kinematics & Compliance test rig converted to a tire test rig. First, it is investigated whether the wheel movements from the parking maneuver can be decomposed into their individual elements on the test bench. In addition, reproducibility studies are carried out and three different methods for determining the aligning torque under camber are presented. Furthermore, measurements for static and dynamic friction values, as well as stiffnesses and the contact patch, are integrated into the new measurement procedure. It becomes apparent that temperature and wear level of the tire play a major role in the reproducibility of the measurements. If the measurement procedure described in this paper is followed exactly, the scatter of the drilling torque can be reduced by up to 24% compared to the old procedure. For the dynamic and the static friction values, the scatter is reduced by about 17% and 22%, respectively. Stiffness scatter can be reduced by up to 16%.\u0000 With the new measurement procedure, the worst-case tire can be reliably determined. The drilling torques correlate with the rack forces and the additional tire characteristics permit finer resolution. After evaluation and interpretation, recommendations for future developments are discussed.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45376360","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}
Tire forming simulation is challenging for Lagrangian finite element method codes due to large changes in the geometry of the tire in the course of molding. This Technical Note briefly describes the use of Arbitrary Lagrangian-Eulerian (ALE) adaptive remeshing in the context of tire molding and curing simulations. The ALE concept generalizes the pure Lagrangian formulation, where the solution within a time step is split into a mesh smoothing step, a history remapping step, and a Lagrangian step. Mesh distortion is reduced in the smoothing step by optimizing the node positions of spatial and material meshes without changing the data structure. The advantage of the ALE approach is demonstrated by a tire forming example.
{"title":"Arbitrary Lagrangian-Eulerian Remeshing in FE Simulations of Tire Forming","authors":"I. Zreid, Y. Wei, M. Kaliske","doi":"10.2346/tire.22.22004","DOIUrl":"https://doi.org/10.2346/tire.22.22004","url":null,"abstract":"\u0000 Tire forming simulation is challenging for Lagrangian finite element method codes due to large changes in the geometry of the tire in the course of molding. This Technical Note briefly describes the use of Arbitrary Lagrangian-Eulerian (ALE) adaptive remeshing in the context of tire molding and curing simulations. The ALE concept generalizes the pure Lagrangian formulation, where the solution within a time step is split into a mesh smoothing step, a history remapping step, and a Lagrangian step. Mesh distortion is reduced in the smoothing step by optimizing the node positions of spatial and material meshes without changing the data structure. The advantage of the ALE approach is demonstrated by a tire forming example.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46826502","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}
Dominic Neumann, J. Friederichs, Mark Harris, M. Weinberger, D. Schramm, C. Bachmann
Virtual steering system layout in the early development phase requires adequate tire models to predict realistic steering rack forces. An accurate representation of parking is particularly important, as the largest steering rack forces occur during this maneuver. Physical tire models are mainly parameterized for rolling conditions. Since the tire exhibits different mechanical behavior under nonrolling conditions, this article introduces a new parameterization procedure for the physical tire model FTire that characterizes the conditions during parking maneuvers. To this end, an additional full vehicle measurement setup is used to understand the tire motions, forces, and torques during parking. It is also shown that a tire model based on a standard parameterization procedure results in steering speed-dependent parking torque deviations of up to 17.5% when compared with component measurements. Thus, new measurement methods are developed to help parameterize the tire model for this maneuver. A linear friction tester is used to determine the friction interaction between tire and road at the relevant relative velocities. In addition, measurements are performed on a tire stiffness test rig, in which translatory and rotatory movements are overlaid. Furthermore, the contact patch shape, ground pressure distribution, and tire outer contour are digitalized and added into the model. A tire model based on the new parking optimized parameterization is then compared with the standard tire modeling approach and component measurements as well as the full vehicle measurements. In conclusion, improvements of up to 12% for drilling torque, up to 15% for longitudinal force, a more realistic lateral stiffness, a more realistic pressure distribution, and improvements of up to 8% when simulating the steering rack force can be stated. After the results are evaluated and interpreted, recommendations for future developments of this parameterization procedure and an extension of the virtual tire model are discussed.
{"title":"Parking-Specific Parameterization Method for FTire","authors":"Dominic Neumann, J. Friederichs, Mark Harris, M. Weinberger, D. Schramm, C. Bachmann","doi":"10.2346/tire.22.21019","DOIUrl":"https://doi.org/10.2346/tire.22.21019","url":null,"abstract":"\u0000 Virtual steering system layout in the early development phase requires adequate tire models to predict realistic steering rack forces. An accurate representation of parking is particularly important, as the largest steering rack forces occur during this maneuver. Physical tire models are mainly parameterized for rolling conditions. Since the tire exhibits different mechanical behavior under nonrolling conditions, this article introduces a new parameterization procedure for the physical tire model FTire that characterizes the conditions during parking maneuvers. To this end, an additional full vehicle measurement setup is used to understand the tire motions, forces, and torques during parking. It is also shown that a tire model based on a standard parameterization procedure results in steering speed-dependent parking torque deviations of up to 17.5% when compared with component measurements. Thus, new measurement methods are developed to help parameterize the tire model for this maneuver. A linear friction tester is used to determine the friction interaction between tire and road at the relevant relative velocities. In addition, measurements are performed on a tire stiffness test rig, in which translatory and rotatory movements are overlaid. Furthermore, the contact patch shape, ground pressure distribution, and tire outer contour are digitalized and added into the model. A tire model based on the new parking optimized parameterization is then compared with the standard tire modeling approach and component measurements as well as the full vehicle measurements. In conclusion, improvements of up to 12% for drilling torque, up to 15% for longitudinal force, a more realistic lateral stiffness, a more realistic pressure distribution, and improvements of up to 8% when simulating the steering rack force can be stated. After the results are evaluated and interpreted, recommendations for future developments of this parameterization procedure and an extension of the virtual tire model are discussed.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48647514","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 tire industry still spends a considerable amount of resources on indoor and outdoor tests during the product development stage. Virtual tests provide conditions to complete this step faster, saving both money and time. Considering that life span and mileage are important issues, especially for truck tire consumers, virtual wear analyses provide valuable information that helps engineers to improve their products. This study aims to exemplify a way to predict tread band wear using the finite element method approach and Archard's wear theory. In addition, it shows the importance of following the vehicle maintenance program as it has an impact on how long the set of tires will last. Tread wear simulation is implemented through user subroutine and adaptive meshing technique, whereas friction energy is calculated using a steady-state analysis at selected working conditions. Data collected from outdoor experiments provide the necessary information to check and validate the analysis. The impact of the lack of appropriate vehicle maintenance on tire wear is evaluated by changing some boundary conditions of the model such as load, inner pressure, and camber and toe angles. The simulation results show good agreement with the information found in the literature.
{"title":"Evaluating Tire Tread Wear and Its Dependence on Tire Working Conditions by Using the Finite Element Method and Archard's Wear Theory","authors":"H. J. Dionísio, A. M. Calhabeu","doi":"10.2346/tire.22.21023","DOIUrl":"https://doi.org/10.2346/tire.22.21023","url":null,"abstract":"\u0000 The tire industry still spends a considerable amount of resources on indoor and outdoor tests during the product development stage. Virtual tests provide conditions to complete this step faster, saving both money and time. Considering that life span and mileage are important issues, especially for truck tire consumers, virtual wear analyses provide valuable information that helps engineers to improve their products. This study aims to exemplify a way to predict tread band wear using the finite element method approach and Archard's wear theory. In addition, it shows the importance of following the vehicle maintenance program as it has an impact on how long the set of tires will last. Tread wear simulation is implemented through user subroutine and adaptive meshing technique, whereas friction energy is calculated using a steady-state analysis at selected working conditions. Data collected from outdoor experiments provide the necessary information to check and validate the analysis. The impact of the lack of appropriate vehicle maintenance on tire wear is evaluated by changing some boundary conditions of the model such as load, inner pressure, and camber and toe angles. The simulation results show good agreement with the information found in the literature.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45318860","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}
This paper aims to devise a method to obtain an empirical friction law for rubber using the Laboratory Abrasion Tester (LAT) 100. The LAT 100 experiments, which aim to measure the side force at various slip angles, loads, and speeds, are carried out, followed by finite element simulation using ABAQUS. A friction law is implemented using a subroutine (UFRIC), which calculates the friction coefficient at each node on the contact patch based on contact pressure and slip velocity at the corresponding node. Coefficients of the frictional law, μ = a + b × e−1/(αp) + c × e−1/(βv), have been estimated by using a series of simulations along with minimizing the error between experiment and simulation side forces. The procedure followed in this paper can be used to fit friction models for rubber using LAT 100 side force experiments.
{"title":"Friction Law for Rubber from Laboratory Abrasion Tester","authors":"Aban Tom Isaiah, K. Ramarathnam","doi":"10.2346/tire.22.21022","DOIUrl":"https://doi.org/10.2346/tire.22.21022","url":null,"abstract":"\u0000 This paper aims to devise a method to obtain an empirical friction law for rubber using the Laboratory Abrasion Tester (LAT) 100. The LAT 100 experiments, which aim to measure the side force at various slip angles, loads, and speeds, are carried out, followed by finite element simulation using ABAQUS. A friction law is implemented using a subroutine (UFRIC), which calculates the friction coefficient at each node on the contact patch based on contact pressure and slip velocity at the corresponding node. Coefficients of the frictional law, μ = a + b × e−1/(αp) + c × e−1/(βv), have been estimated by using a series of simulations along with minimizing the error between experiment and simulation side forces. The procedure followed in this paper can be used to fit friction models for rubber using LAT 100 side force experiments.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46236507","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}
Craig Burkhart, B. Jiang, G. Papakonstantopoulos, P. Polińska, Hongyi Xu, R. J. Sheridan, L. Brinson, W. Chen
Tread compounding has always been faced with the simultaneous optimization of multiple performance properties, most of which have tradeoffs between the properties. The search for overcoming these conflicting tradeoffs have led many companies in the tire industry to discover and develop material physics-based platforms. This report describes some of our efforts to quantify compound structures and properties at multiple scales, and their subsequent application in compound design. Integration of experiment and simulation has been found to be critical to highlighting the levers in data-driven multiscale compound tread design.
{"title":"Data-Driven Multiscale Science for Tread Compounding","authors":"Craig Burkhart, B. Jiang, G. Papakonstantopoulos, P. Polińska, Hongyi Xu, R. J. Sheridan, L. Brinson, W. Chen","doi":"10.2346/tire.22.21003","DOIUrl":"https://doi.org/10.2346/tire.22.21003","url":null,"abstract":"\u0000 Tread compounding has always been faced with the simultaneous optimization of multiple performance properties, most of which have tradeoffs between the properties. The search for overcoming these conflicting tradeoffs have led many companies in the tire industry to discover and develop material physics-based platforms. This report describes some of our efforts to quantify compound structures and properties at multiple scales, and their subsequent application in compound design. Integration of experiment and simulation has been found to be critical to highlighting the levers in data-driven multiscale compound tread design.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45888843","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}
Guanqun Liang, Yan Wang, Mario A. García, Tong Zhao, Zhe Liu, M. Kaliske, Yintao Wei
Efforts to improve the performance and safety of vehicles include placing active sensing components (e.g., embedded microsensors) within tires result in intelligent tires. One application of intelligent tire is tire force estimation based on accelerometers. However, its development is limited due to the difficulty of relating the tire force to kinematical information by model-based theory. In this manuscript, a universal approach to tire forces estimation by the accelerometer-based intelligent tire is formulated and experimentally validated. First, a microelectromechanical system accelerometer-based intelligent tire prototype is established with the function of on-board monitoring of tire forces. Then, a theoretical rolling kinematics model is proposed for illustrating the mechanisms of acceleration fields, resulting from the coupling effect of rigid body motion and elastic deformation. An analytical model is formulated to estimate the vertical force in real time. Furthermore, the beam model is adopted to describe lateral deformations of the tire belt, directly linking lateral acceleration and lateral force. Finally, the lateral force can be estimated by lateral acceleration and vertical force already estimated. Based on a universal analytical model, the lateral force estimation method realizes high accuracy under different circumstances, even with unified coefficients, by clarifying and eliminating the influence of ply steer. A field test and two bench experiments have been conducted to fully validate the developed model. It can be concluded that the theoretical-analysis-based estimation model realizes an encouraging tire force estimation application with an intelligent tire hardware system.
{"title":"A Universal Approach to Tire Forces Estimation by Accelerometer-Based Intelligent Tire: Analytical Model and Experimental Validation","authors":"Guanqun Liang, Yan Wang, Mario A. García, Tong Zhao, Zhe Liu, M. Kaliske, Yintao Wei","doi":"10.2346/tire.21.21001","DOIUrl":"https://doi.org/10.2346/tire.21.21001","url":null,"abstract":"\u0000 Efforts to improve the performance and safety of vehicles include placing active sensing components (e.g., embedded microsensors) within tires result in intelligent tires. One application of intelligent tire is tire force estimation based on accelerometers. However, its development is limited due to the difficulty of relating the tire force to kinematical information by model-based theory. In this manuscript, a universal approach to tire forces estimation by the accelerometer-based intelligent tire is formulated and experimentally validated. First, a microelectromechanical system accelerometer-based intelligent tire prototype is established with the function of on-board monitoring of tire forces. Then, a theoretical rolling kinematics model is proposed for illustrating the mechanisms of acceleration fields, resulting from the coupling effect of rigid body motion and elastic deformation. An analytical model is formulated to estimate the vertical force in real time. Furthermore, the beam model is adopted to describe lateral deformations of the tire belt, directly linking lateral acceleration and lateral force. Finally, the lateral force can be estimated by lateral acceleration and vertical force already estimated. Based on a universal analytical model, the lateral force estimation method realizes high accuracy under different circumstances, even with unified coefficients, by clarifying and eliminating the influence of ply steer. A field test and two bench experiments have been conducted to fully validate the developed model. It can be concluded that the theoretical-analysis-based estimation model realizes an encouraging tire force estimation application with an intelligent tire hardware system.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44368291","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}
While in nature, snow properties change from day to day or even minute by minute, one of the great advantages of lab tests is the stability and reproducibility of testing conditions. In our labs at the Institute of Dynamics and Vibration Research, Leibniz Universität Hannover, we currently run three test rigs that are able to conduct tests with tire tread blocks on snow and ice tracks [1,2]: High-Speed Linear Tester (HiLiTe) [3], Portable Friction Tester (PFT), and Reproducible Tread Block Mechanics in Lab (RepTiL). In the past years, we have run a project on the influence of snow track properties on friction and traction test results with those test rigs. In this article, we will present a first excerpt of the results concentrating on the RepTiL test rig. Because this rig reproduces the movement of rolling tire tread blocks [2], we executed a test campaign with special samples for the analysis of snow friction mechanics. We evaluated penetration into the snow, maximum longitudinal force level, and longitudinal force gradient. On the other hand, we varied the snow density while preparing our tracks to assess the influence of the snow track density on the friction mechanics. In parallel, we have accompanied our experiments with discrete element method simulations to better visualize and understand the physics behind the interaction between snow and samples. The simulation shows the distribution of induced stress within the snow tracks and resulting movement of snow particles. Hypotheses for the explanation of the friction behavior in the experiments were confirmed. Both tests and simulations showed, with good agreement, a strong influence of snow density and sample geometry.
{"title":"Investigation of the Influence of Snow Track Density on Tire Tread Block Traction by Experiments and Discrete Element Method Simulation","authors":"Michael Hindemith, J. Heidelberger, M. Wangenheim","doi":"10.2346/tire.21.20023","DOIUrl":"https://doi.org/10.2346/tire.21.20023","url":null,"abstract":"\u0000 While in nature, snow properties change from day to day or even minute by minute, one of the great advantages of lab tests is the stability and reproducibility of testing conditions. In our labs at the Institute of Dynamics and Vibration Research, Leibniz Universität Hannover, we currently run three test rigs that are able to conduct tests with tire tread blocks on snow and ice tracks [1,2]: High-Speed Linear Tester (HiLiTe) [3], Portable Friction Tester (PFT), and Reproducible Tread Block Mechanics in Lab (RepTiL). In the past years, we have run a project on the influence of snow track properties on friction and traction test results with those test rigs. In this article, we will present a first excerpt of the results concentrating on the RepTiL test rig. Because this rig reproduces the movement of rolling tire tread blocks [2], we executed a test campaign with special samples for the analysis of snow friction mechanics. We evaluated penetration into the snow, maximum longitudinal force level, and longitudinal force gradient. On the other hand, we varied the snow density while preparing our tracks to assess the influence of the snow track density on the friction mechanics. In parallel, we have accompanied our experiments with discrete element method simulations to better visualize and understand the physics behind the interaction between snow and samples. The simulation shows the distribution of induced stress within the snow tracks and resulting movement of snow particles. Hypotheses for the explanation of the friction behavior in the experiments were confirmed. Both tests and simulations showed, with good agreement, a strong influence of snow density and sample geometry.","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46535945","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}
Pub Date : 2021-10-01DOI: 10.2346/1945-5852-49.4.332
{"title":"Tire Science and Technology Author Index to Volume 49 2021","authors":"","doi":"10.2346/1945-5852-49.4.332","DOIUrl":"https://doi.org/10.2346/1945-5852-49.4.332","url":null,"abstract":"","PeriodicalId":44601,"journal":{"name":"Tire Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47101156","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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