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Development Of A Tire Pavement Contact Stress Model Based On Artificial Neural Networks
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Book Synopsis Development of a Tire/pavement Contact-stress Model Based on Artificial Neural Networks by : Moustafa El-Gindy
Download or read book Development of a Tire/pavement Contact-stress Model Based on Artificial Neural Networks written by Moustafa El-Gindy and published by . This book was released on 2001 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Public Roads written by and published by . This book was released on 2001 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Innovations in Vehicle Design and Development by : Imtiaz Haque
Download or read book Innovations in Vehicle Design and Development written by Imtiaz Haque and published by . This book was released on 1999 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Monthly Catalog of United States Government Publications by :
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 2001 with total page 838 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Tire-Pavement Contact Stress with 3D Finite-Element Model?Part 1 by : P. Cao
Download or read book Tire-Pavement Contact Stress with 3D Finite-Element Model?Part 1 written by P. Cao and published by . This book was released on 2016 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vehicles pass their loads through tires onto pavements. Traditionally, the vertical contact pressure is assumed to uniformly distribute in a rectangle or circular area, whereas the shear contact pressure is ignored in pavement design. Experiments have demonstrated that the interaction between the tire and the pavement surface is very complicated. The contact area is not a regular shape and the distribution of contact pressure is not uniform. However, experimental approaches to measure contact pressure are usually time and energy consuming, whereas the results are subject to errors introduced by measurement sensors. On the other hand, numerical simulation can describe the interaction between tire and pavement surface under all circumstances, such as various driving conditions, different tread types, and so on. In this paper, a three-dimensional finite-element model for tires was developed. The model was validated by the static test data. Then the interactions of different tires with pavement were analyzed, including the vertical and shear contact-pressure distributions on tires and on pavement surfaces. The influences of pavement friction and load level on the contact-pressure distributions of tires and pavement were investigated as well. It was found that vertical and shear contact pressures on tires and pavement were quite different when the type of tire or the friction changed. The contact-pressure distribution was found not uniform and the shape of contact area changed as the load level varied. The complicated interactions between different tires and pavement indicate that sophisticated tire models are necessary to obtain more accurate pavement responses.
Book Synopsis Annual Report by : Pennsylvania Transportation Institute
Download or read book Annual Report written by Pennsylvania Transportation Institute and published by . This book was released on 1999 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Analysis of Tire-pavement Interaction and Pavement Responses Using a Decoupled Modeling Approach by : Hao Wang
Download or read book Analysis of Tire-pavement Interaction and Pavement Responses Using a Decoupled Modeling Approach written by Hao Wang and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The proper understanding of tire-pavement interaction is important for the accurate analysis of load-induced stresses and strains in the pavement structure. This dissertation focuses on the analysis of the mechanism of tire-pavement interaction and the effect of tire-pavement interaction on pavement responses using a decoupled modeling approach. First, an air-inflated three-dimensional (3-D) finite element (FE) tire model was built and the interaction between a tire and a non-deformable pavement surface was simulated. The tire is modeled as a composite structure including rubber and reinforcement. The steady-state tire rolling process was simulated using an Arbitrary Lagrangian Eulerian (ALE) formulation. The developed tire-pavement interaction model is used to evaluate the mechanism of load distribution at the tire-pavement interface under various tire loading and rolling conditions. After that, a 3-D FE model of flexible pavement was developed to analyze pavement responses under various loading scenarios. This model utilizes the implicit dynamic analysis, simulates vehicular loading as a continuous moving load, and incorporates 3-D contact stresses at the tire-pavement interface. In the pavement model, the asphalt layer is modeled as a linear viscoelastic material and the granular base layer is modeled as a nonlinear anisotropic material. The FE pavement model was used to analyze critical pavement responses in thin and thick asphalt pavements considering different damage mechanisms. This dissertation concludes that knowledge of tire-pavement contact stress distributions is critical for pavement response prediction. Most importantly, the non-uniform distribution of vertical contact stresses and the localized tangential contact stresses should be considered in the mechanistic-empirical pavement design. The contact stress distributions at the tire-pavement interface are affected by vehicle loading (wheel load and tire inflation pressure), tire configuration (dual-tire assembly and wide-base tire), vehicle maneuvering (braking/acceleration and cornering), and pavement surface friction. Therefore, pavement damage should be quantified using accurate loading inputs that are represented by realistic tire-pavement contact stress distributions. Thin and thick asphalt pavements fail in different ways. Multiple distress modes could occur in thin asphalt pavements, including bottom-up fatigue cracking and rutting in each pavement layer. It was found that the interaction between the viscoelastic asphalt layer and the nonlinear anisotropic granular base layer plays an important role for the stress distribution within a thin asphalt pavement structure under moving vehicular loading. In thick asphalt pavements, near-surface cracking is a critical failure mechanism, which is affected by the localized stress states and pavement structure characteristics. Particularly, the effect of shear stress on the formation of near-surface cracking at multi-axial stress states is important and can not be neglected, especially at high temperatures.
Book Synopsis Evaluation of Effects of Tire Size and Inflation Pressure on Tire Contact Stresses and Pavement Response by :
Download or read book Evaluation of Effects of Tire Size and Inflation Pressure on Tire Contact Stresses and Pavement Response written by and published by . This book was released on 2006 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: A specific objective was to establish how tire contact stresses may be modeled in existing layered elastic programs to better approximate the effects of non-uniform tire contact pressure distributions, and account for differences in tire construction, tire load, and tire inflation pressure on predicted pavement response. To this end, researchers assembled a data base of measured tire contact stresses and performed a comparative evaluation of methods for representing tire contact pressure distributions in existing models to predict performance-related pavement response variables. A computer program called TireView was developed that provides estimates of tire contact area as a function of tire type, tire load, and tire inflation pressure and predicts the stress distribution at the tire-pavement interface based on polynomial interpolations of measured tire contact stresses in the data base. A method for predicting pavement response using layered elastic analysis is proposed that is based on the predicted tire contact area.
Book Synopsis Proceedings of the ... ASME Design Engineering Technical Conferences by :
Download or read book Proceedings of the ... ASME Design Engineering Technical Conferences written by and published by . This book was released on 2003 with total page 946 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Dynamics of Vehicle-Road Coupled System by : Shaopu Yang
Download or read book Dynamics of Vehicle-Road Coupled System written by Shaopu Yang and published by Springer. This book was released on 2015-04-29 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vehicle dynamics and road dynamics are usually considered to be two largely independent subjects. In vehicle dynamics, road surface roughness is generally regarded as random excitation of the vehicle, while in road dynamics, the vehicle is generally regarded as a moving load acting on the pavement. This book suggests a new research concept to integrate the vehicle and the road system with the help of a tire model, and establishes a cross-subject research framework dubbed vehicle-pavement coupled system dynamics. In this context, the dynamics of the vehicle, road and the vehicle-road coupled system are investigated by means of theoretical analysis, numerical simulations and field tests. This book will be a valuable resource for university professors, graduate students and engineers majoring in automotive design, mechanical engineering, highway engineering and other related areas. Shaopu Yang is a professor and deputy president of Shijiazhuang Tiedao University, China; Liqun Chen is a professor at Shanghai University, Shanghai, China; Shaohua Li is a professor at Shijiazhuang Tiedao University, China.
Book Synopsis Tire-Pavement Contact Stress With 3D Finite-Element Model?Part 2 by : P. Cao
Download or read book Tire-Pavement Contact Stress With 3D Finite-Element Model?Part 2 written by P. Cao and published by . This book was released on 2015 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heavy vehicles increase on highways in China year by year. Heavy loads are among the most important factors causing pavement distresses. The distribution of contact stresses between tires and pavement surface greatly influences the initiation and propagation of pavement distresses, especially for the top-down cracking. Therefore, to accurately and precisely describe pavement responses, the distribution of contact stresses should be first investigated thoroughly. This study focuses on simulating the contact stresses between all-steel tires on heavy vehicles and the pavement surface. A 3D finite-element model was proposed and used to simulate the distribution of contact stresses in different conditions of tires, including standstill, free rolling, accelerating rolling, and decelerating rolling conditions. This model was validated by previous study of the authors. There were three loading levels used in this study, including 20 kN, 40 kN, and 60 kN. In the standstill condition, the maximum pressures on pavement surface were simulated as 1.2 MPa, 1.2 MPa, and 2.4 MPa in 20 kN, 40 kN, and 60 kN loading levels, respectively, which were much higher than 0.7 MPa, the standard contact pressure in pavement design specification in China. An interesting phenomenon was observed that when the load passed a certain value, the width of contact area kept constant, whereas the length of contact area was prolonged. And the length of the contact area prolonged linearly with the increase of load. Based on this phenomenon, the Hertz contact theory was applied to simplify the traditional 3D finite-element model. In the simplified model, the complicated 3D all-steel tire was simplified to an equivalent medium. The 3D finite-element model and the simplified model were compared with the analytic method. This indicates that the simplified model can simulate the contact stress of all-steel tires closely to the analytic results (no more than 10 % difference) and greatly improves the calculation efficiency.
Book Synopsis Evaluation of Pavement Damage Due to New Tire Designs by : Imad L. Al-Qadi
Download or read book Evaluation of Pavement Damage Due to New Tire Designs written by Imad L. Al-Qadi and published by . This book was released on 2009 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Tire/pavement Contact Force Modeling. Investigation of the Tire/pavement Interaction Mechanism - Phase III. Final Report, Volume 1 by : Allen C. Eberhardt
Download or read book Tire/pavement Contact Force Modeling. Investigation of the Tire/pavement Interaction Mechanism - Phase III. Final Report, Volume 1 written by Allen C. Eberhardt and published by . This book was released on 1987 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Automobile Design Liability, 3d by : Richard M. Goodman
Download or read book Automobile Design Liability, 3d written by Richard M. Goodman and published by . This book was released on 1994 with total page 2324 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Tire-pavement Interaction, Experimental Measurements and Modeling by : Mohammad O. Al-Assi
Download or read book Tire-pavement Interaction, Experimental Measurements and Modeling written by Mohammad O. Al-Assi and published by . This book was released on 2019 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: Providing an adequate level of skid resistance is essential for the safety of motorists. Previous studies demonstrated that the number of crashes is reduced if pavements have sufficient friction, especially in wet conditions. Adequate pavement friction prevents the vehicle from sliding on the pavement surface and provides the grip needed to maintain control over the vehicle. The first phase of this study investigated experimentally the two major friction mechanisms (i.e., adhesion and hysteresis) that contribute to tire-pavement friction. It is postulated that the adhesion between rubber tires and pavements is highly influenced by the surface free energy. However, there are no previous studies carried out to investigate the adhesion between rubber tires and pavements using the surface free energy. The results demonstrated that adhesion friction can be quantified by measuring the surface free energy components of pavement surface aggregates and rubber materials. There was a fair correlation between the adhesive bond energy and the measured coefficient of friction. Higher adhesion between rubber materials and pavement surface provided higher friction. These results provide a fundamental understanding of the mechanisms of rubber-pavement friction and verification of the relationship between adhesion and friction. In addition, there was a strong correlation between friction and rubber rheological properties. Rubber materials with lower modulus provided higher friction compared to those with higher modulus. These results explain the change in skid resistance with temperature throughout the year. The second phase of this study examined different factors that affect skid resistance of pavement surfaces. These parameters included macrotexture, microtexture, and driving speed. The macrotexture of the pavement is related to aggregate gradation of the mix or surface texture pattern. The microtexture is influenced by the roughness of the aggregate particles and their resistance to abrasion and polishing under traffic. This study proposed a new model that can be used to estimate the skid number at a given speed between 20 mph and 60 mph as a function of both macrotexture and microtexture of pavement surface. This model was developed based on the measured frictional characteristics of field test sections. The proposed model can be used if the full-scale friction tester is not available or cannot be used due to the limited length of the test section (e.g., bridge deck). In addition, the model provides a tool to the pavement engineers to ensure adequate skid resistance at various operation speeds during the mix design stage and before the mix is used in the field. A given mix design can be modified to improve its frictional characteristics at early stage which leads to cost savings often spent on the application of surface treatments. The third phase of this study utilized the close-range photogrammetry (CRP) technique to measure the pavement macrotexture and microtexture. Texture parameters were calculated from the collected and analyzed images of the pavement surface. The results of the CRP texture measurements were compared to standard test methods. The CRP texture measurements had excellent correlation with the standard methods; however, the CRP offers simple and accurate, yet inexpensive alternative to the current methods used to measure surface macrotexture and microtexture. In addition, the CRP texture parameters were incorporated in the Persson friction model to predict skid friction as a function of rubber properties. The results demonstrated excellent correlation between measured and predicted friction. This study greatly simplified the texture parameter calculations needed in the Persson friction model with good accuracy.The last component of this study developed a 3D finite element model to investigate the effect of surface characteristics along with rubber properties on the contact stress between the standard skid test tire and pavement surface. Such simulation provides an in-depth understanding of tire-pavement interaction that would require expensive resources to examine in the field. Study parameters included various coefficient of friction, texture (e.g., smooth, and grooved), tire rolling conditions (fully skidding and free rolling) as well as temperature. The developed 3D FE model of the test tire was first validated with laboratory measurements before it was used to examine the effect of the study parameters on tire-pavement contact stresses. The results of the finite element simulations demonstrated that the stress distribution at the tire-pavement interface is non-uniform with maximum values towards the edges of the tire. These findings were consistent with the wearing pattern of the test tire in the field. In addition, the results also demonstrated that the shear stresses increased with surface friction while there was no significant change in the vertical stresses. The grooved surface exhibited higher vertical and shear stresses compared to pavement with smooth texture. The grooved texture is used to improve skid resistance and reduce the noise of pavement surfaces. In addition, temperature was found to have significant impact on the stresses at the tire-pavement interface. The finite element simulation results agreed with the laboratory and field measurements of pavement friction.
Book Synopsis Analytical Determination of Normal Contact Stresses for Arbitrary Geometries with Application to the Tire/Pavement Interaction Mechanism by : TG. Clapp
Download or read book Analytical Determination of Normal Contact Stresses for Arbitrary Geometries with Application to the Tire/Pavement Interaction Mechanism written by TG. Clapp and published by . This book was released on 1985 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: A method for approximating the normal contact pressure distribution and the contact length associated with tire/pavement interaction has been developed using deformed tire geometry as a measured function of position. The mathematical development of the method is based on classic contact stress theory for contact between an elastic half plane and a rigid indenter. The unknown pressure distribution satisfies a linear integral equation and is approximated by an M-order polynomial with M + 1 unknown coefficients. The unknown coefficients are found by evaluation of both sides of the integral equation at M + 1 points, and the polynomial pressure distribution is plotted. The order, M, of the pressure distribution polynomial is sequentially increased until the pressure distribution stabilizes, completing the solution process. The contact length is approximated from sign changes in the pressure distribution caused by the geometric characteristics of the deformation curve for the tire not in contact with the pavement surface.
Book Synopsis Pavement Response Analysis and Modulus Back-calculation for Highway and Airfield Flexible Pavements by : Maoyun Li
Download or read book Pavement Response Analysis and Modulus Back-calculation for Highway and Airfield Flexible Pavements written by Maoyun Li and published by . This book was released on 2017 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: The analysis of pavement responses is important for better understanding of pavement performance and accurate estimation of pavement service life. This dissertation aims to study flexible pavement responses using forward and inverse analysis. The first objective is development of axisymmetric finite element (FE) models that can simulate FWD loading on the pavement system. After that, the backcalculation of pavement layer moduli from FWD testing was studied by means of soft computing techniques such as Artificial Neural Networks (ANNs) and Genetic Algorithms (GA). The axisymmetric FE models were used to generate a synthetic database. The ANN-GA backcalculating program is developed to assess existing pavement condition after the training and verification using the synthetic database. The second objective of this dissertation is to investigate airfield flexible pavement responses under aircraft loading in consideration of the realistic aircraft tire-pavement interaction. An advanced three-dimensional (3-D) finite element (FE) model was developed to simulate heavy aircraft loading with high tire pressure. The aircraft loading was simulated as moving wheels having non-uniform contact stress distributions. Different tire rolling conditions caused by aircraft ground maneuvering were simulated, including free rolling, full-braking, and turning. The multi-wheel aircraft loading was modeled in two-wheel, four-wheel and six-wheel assembly. The analysis concludes that FWD deflections were affected by dynamic analysis, temperature gradient, bedrock depth, asphalt layer delamination, viscoelasticity, and unbound material nonlinearity. After validated with the field measurements in the long-term pavement performance program (LTPP) database, the developed ANN-GA program can be used to obtain damaged dynamic moduli of asphalt concrete and evaluate in-situ pavement conditions from structural point of view, which facilitates pavement overlay design procedure using Mechanistic-Empirical Pavement Design Guideline (MEPDG). The investigation on airfield flexible pavement emphasized the importance of considering non-uniform tire contact stresses and temperature profiles in airfield pavement analysis. For the aircraft ground maneuvering, aircraft braking or turning significantly increases shear failure potential in asphalt layer. The analysis of stress states would facilitate evaluation of the shear failure potential at airfield asphalt pavements. Finally, the investigation on multi-wheel aircraft loading indicates that the six-wheel gear configuration would cause more fatigue cracking and near-surface cracking potential than dual-wheel and four-wheel gears.
