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Sensitivity Analysis of Tire-Soil Interaction Using Finite Element Analysis and Smoothed Particle Hydrodynamics Techniques

University of Ontario Institute of Technology-Zeinab El-Sayegh
UOIT-Mirwais Sharifi, Moustafa El-Gindy
Published 2019-04-02 by SAE International in United States
This paper presents the modelling, calibration and sensitivity analysis of LETE sand soil using Visual Environment’s Pam Crash. LETE sand is modelled and converted from Finite Element Analysis mesh (FEA) to Smooth-particle hydrodynamics (SPH). The sand is then calibrated using terramechanics published data by simulating a pressure sinkage test and shear box test using the SPH LETE sand particles. The material properties such as tangent modulus, yield strength and bulk modulus are configured so the simulation’s results match those of theoretical values. Sensitivity analysis of the calibrated LETE sand material is then investigated. The sensitivity analysis includes mesh size, plate geometry, smoothing length, max smoothing length, artificial viscosity and contact thickness. The effect of these parameters on the sand behavior is analyzed. Finally, SPH LETE Sand is used to determine the rolling resistance coefficient of FEA off-road truck tire size 315/80R22.5 for different mesh size sand particles. The results found within this paper will be continued in regard to achieving better understanding of vehicle dynamics for tire-terrain interaction.
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Design and Optimization of a Robust Active Trailer Steering System for Car-Trailer Combinations

University of Ontario Institute of Technology-Mutaz Keldani, Khizar Qureshi, Yuping He, Ramiro Liscano
Published 2019-04-02 by SAE International in United States
This paper presents a robust active trailer steering (ATS) controller for car-trailer combinations. ATS systems have been proposed and explored for improving the lateral stability and enhancing the path-following performance of car-trailer combinations. Most of the ATS controllers were designed using the linear quadratic regulator (LQR) technique. In the design of the LQR-based ATS controllers, it was assumed that all vehicle and operating parameters were constant. In reality, vehicle and operating parameters may vary, which may have an impact on the stability of the combination. For example, varied vehicle forward speed and trailer payload may impose negative impacts on the directional performance of the car-trailer combination. Thus, the robustness of the conventional LQR-based ATS controllers is questionable. To address this problem, we propose a gain-scheduling LQR-based ATS controller. In the design of the proposed ATS controller, at each operating point, the ATS controller is designed using the LQR technique. At an operating point between two established adjacent operating points, the control gain matrix of the controller is determined using an interpolation method. To further improve…
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Safety and Lateral Dynamics Improvement of a Race Car Using Active Rear Wing Control

University of Ontario Institute of Technology-Mohammed Hammad, Khizar Qureshi, Yuping He
Published 2019-04-02 by SAE International in United States
As the forward speed of a car increases, the safety of the vehicle and the driver becomes a more significant concern. Active aerodynamic control can effectively enhance the lateral stability of high speed vehicles over tight cornering maneuvers. A split rear wing has been proposed. By means of manipulating the attack angles for the right and/or left parts of the split rear wing, a favorable yaw moment may be achieved to ensure the lateral stability of the vehicle. However, active control of the split rear wing has not been adequately explored. This paper proposes a novel active split rear wing, which can improve the lateral stability over tight cornering maneuvers, and will not degrade the longitudinal dynamics of the vehicle. A Linear Quadratic Regulator (LQR) based controller for the active split rear wing is designed using a linear vehicle model. In order to examine the performance of the active split rear wing, Numerical simulation is carried out using the LQR based controller and a yaw-plane vehicle model designed in MATLAB. The effectiveness of the proposed…
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Investigation and Development of Underbody Aerodynamic Drag Reduction Devices for Trailer Trucks

University of Ontario Institute of Technology-Mohamed Ibrahim, Martin Agelin-chaab
Published 2018-04-03 by SAE International in United States
It is well known that the underbody region of a tractor-trailer is responsible for up to 30% of the aerodynamic drag. This is the highest drag created by any region of a tractor-trailer. There are a number of underbody drag-reduction devices available on the market but they create a few operational issues, such as low ground clearance and ice collection, which inhibit their mass market appeal. In this paper, a novel concept of an underbody aerodynamic device is developed and investigated. The underbody device is a combination of a ramp and a side skirt; which are optimized simultaneously. In addition, the device is made collapsible to facilitate easy storage when not in use (i.e., city driving). NASA’s Generic Conventional Model (GCM); a 1/8th scale model of a generic class-8 tractor-trailer is used to evaluate and optimize the concept. The GCM allows the concept to be applicable to a wider range of tractor-trailers. The studies were conducted using the RANS based turbulence model, k-ω SST in ANSYS Fluent. The simulations were validated with NASA’s experimental data…
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Modeling of Tire-Wet Surface Interaction Using Finite Element Analysis and Smoothed-Particle Hydrodynamics Techniques

University of Ontario Institute of Technology-Zeinab El-Sayegh, Moustafa El-Gindy
Volvo Group Trucks Technology-Inge Johansson, Fredrik Oijer
Published 2018-04-03 by SAE International in United States
This paper focuses on predicting the rolling resistance and hydroplaning of a wide base truck tire (Size: 445/50R22.5) on dry and wet surfaces. The rolling resistance and hydroplaning are predicted at various inflation pressures, loads, velocities, and water depths. The wide base truck tire was previously modeled and validated using Finite Element Analysis (FEA) technique in virtual performance software (Pam-Crash). The water is modeled using Smoothed-Particle Hydrodynamics (SPH) method and Murnaghan equation of state. A water layer is first built on top of an FEA rigid surface to represent a wet surface. The truck tire is then inflated to the desired pressure. A vertical load is then applied to the center of the tire. For rolling resistance tests variable constant longitudinal speeds are applied to the center of the tire. The forces in the vertical and longitudinal directions are computed, and the rolling resistance is calculated. The effect of the longitudinal speed on rolling resistance on the wet surface also includes the prediction of the hydroplaning speed. The results are analyzed, and the effect of…
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A Review of Car-Trailer Lateral Stability Control Approaches

University of Ontario Institute of Technology-Smitha Vempaty, Yuping He
Published 2017-03-28 by SAE International in United States
Ensuring the lateral stability and handling of a car-and-trailer combination remains one of the challenges in safety system design and development for articulated vehicles. This paper reviews the state-of-the-art approaches for car-trailer lateral stability control. A literature review covering the effects of external factors, such as aerodynamic forces, tire forces, and road & climatic conditions, is presented. To address the effects of these factors, researchers have previously investigated numerous passive and active safety control techniques. This paper intends to identify the inadequacies of the passive safety approaches and analyzes promising active-control schemes, such as active trailer steering control (ATSC), active trailer braking (ATB) and model reference adaptive controller (MRAC). A comparative study of these control strategies in terms of applicability and cost effectiveness is performed.
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Non-Linear Bifurcation Stability Analysis for Articulated Vehicles with Active Trailer Differential Braking Systems

SAE International Journal of Materials and Manufacturing

University of Ontario Institute of Technology-Tao Sun, Eungkil Lee, Yuping He
  • Journal Article
  • 2016-01-0433
Published 2016-04-05 by SAE International in United States
This paper presents nonlinear bifurcation stability analysis of articulated vehicles with active trailer differential braking (ATDB) systems. ATDB systems have been proposed to improve stability of articulated vehicle systems to prevent unstable motion modes, e.g., jack-knifing, trailer sway and rollover. Generally, behaviors of a nonlinear dynamic system may change with varying parameters; a stable equilibrium can become unstable and a periodic oscillation may occur or a new equilibrium may appear making the previous equilibrium unstable once the parameters vary. The value of a parameter, at which these changes occur, is known as “bifurcation value” and the parameter is known as the “bifurcation parameter”. Conventionally, nonlinear bifurcation analysis approach is applied to examine the nonlinear dynamic characteristics of single-unit vehicles, e.g., cars, trucks, etc. Little attention has been paid to investigate the feasibility and effectiveness of the bifurcation analysis method for nonlinear stability analysis of articulated vehicles under varied operating conditions, e.g., varied forward speed and trailer payload. This motivates the research to examine stability boundaries of equilibrium and limit cycles in the parameter space and…
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Integrated Aero-Thermal Testing of a Race Car in a Full Scale Climatic Wind Tunnel

University of Ontario Institute of Technology-Abdalla Abdel-Rahman, Martin Agelin-Chaab, Gary Elfstrom, John Komar
Published 2016-04-05 by SAE International in United States
Wind tunnels with integrated aerodynamic and thermodynamic testing with yaw capabilities are not common. In this study however, an integrated aerodynamic and thermodynamic testing system with yaw capabilities is developed and applied in the climatic wind tunnel at the University of Ontario-Institute of Technology (UOIT). This was done by installing an incremental force measuring system (FMS) on the large turntable that features a chassis dynamometer. The testing system was utilized to implement an integrated aero-thermal test on a full-scale race car. An efficient testing protocol was developed to streamline the integrated testing process. The FMS was used to enhance the test car’s stability, cornering speed, and fuel efficiency by using aerodynamic devices. These objectives were achieved by installing a high rear wing to increase the rear downforce, a modified front splitter extension to produce a front downforce gain, and front canards to contribute to drag reduction. In addition, a thermodynamic test was conducted to study the effect of yaw on upperbody and underbody temperature distribution during the car’s operational condition. Temperature analysis from this test…
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Determining the Vertical and Longitudinal First Mode of Vibration of a Wide Base FEA Truck Tire

University of Ontario Institute of Technology-Kristian Lee Lardner, Moustafa El-Gindy
Volvo Group Trucks Technology-Fredrik Oijer, Inge Johansson, David Philipps
Published 2016-04-05 by SAE International in United States
The purpose of this study is to determine the effect of tire operating conditions, such as the tire inflation pressure, speed, and load on the change of the first mode of vibration. A wide base FEA tire (445/50R22.5) is virtually tested on a 2.5m diameter circular drum with a 10mm cleat using PAM-Crash code. The varying parameters are altered separately and are as follows: inflation pressure, varying from 50 psi to 165 psi, rotational speed, changing from 20 km/h to 100 km/h, and the applied load will fluctuate from 1,500 lbs. to 9000 lbs. Through a comparison of previous literature, the PAM-Crash FFT algorithmic results have been validated.
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A Comparative Study of Active Control Strategies for Improving Lateral Stability of Car-Trailer Systems

University of Ontario Institute of Technology-Rafay Shamim, Md Manjurul Islam, Yuping He
Published 2011-04-12 by SAE International in United States
This paper examines the performance of different active control strategies for improving lateral stability of car-trailer systems using numerical simulations. For car-trailer systems, three typical unstable motion modes, including trailer swing, jack-knifing and roll-over, have been identified. These unstable motion modes represent potentially hazardous situations. The effects of passive mechanical vehicle parameters on the stability of car-trailer systems have been well addressed. For a given car-trailer system, some of these passive parameters, e.g., the center of gravity of the trailer, are greatly varied under different operating conditions. Thus, lateral stability cannot be guaranteed by selecting a specific passive parameter set. To address this problem, various active control techniques have been proposed to improve handling and stability of car-trailer systems. Feasible control methods involve active trailer steering control (ATSC) and active trailer braking (ATB). Recently, a variable geometry approach (VGA) has been investigated. The essence of this method is to actively control the lateral displacement of the car-trailer hitch in order to improve high-speed stability of the vehicle system. To derive the three controllers, their respective…
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