The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform
Carroll Smith - One of the best experts on this subject based on the ideXlab platform.
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Effects of Suspension Geometry and Stiffness Asymmetries n Wheel Loads During Steady Cornering for a Winston Cup Car (962531)
Racing Chassis and Suspension Design, 1Co-Authors: Carroll SmithAbstract:Tuning a race car for good handling requires accurate prediction of the tire normal loads and tire orientation as specified by steer and camber angles. This paper describes the development and examples of the application of computer models which have been developed to predict Suspension Geometry characteristics and wheel loads for Winston Cup cars running on banked tracks. Example cases are presented illustrating the effects of roll center movement, front spring split (different rates right to left). and cross weight percentage (wedge).
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The Effects of Local Spring Perch Flexibility on Suspension Geometry of a Winston Cup Race Car (983032)
Racing Chassis and Suspension Design, 1Co-Authors: Carroll SmithAbstract:In order to achieve predictable handling of a race car, local mounts connecting Suspension components to the chassis should be sufficiently rigid to minimize unwanted local deflection which may adversely affect Suspension Geometry. In this work, the effects of local chassis flexibility of the spring perch on roll stiffness, tire camber change, and steer angle change are determined from a finite element model (FEM) of a Winston Cup race car. Details such as side gussets, supporting brackets, and local curvature of the frame rail spring pocket are included in a shell model of the spring perch. The local shell model of the spring perch is integrated with the global finite element stiffness model of the chassis and Suspension consisting of an assembly of beam and shell elements.A parametric study on the effects of thickness changes for seven different areas of the spring perch has been performed. Tire camber change, steer angle change, and chassis roll stiffness are plotted as a function of thickness variation for each of the seven perch areas. Results indicate that the surface with the most adverse affects on torsional stiffness, roll stiffness, and camber changes, resulting from reduced thickness, is the principal spring support plate. Stiffness increases may be achieved by increasing the thickness of the spring plate, spring pocket, and frame rail box beam, but the greatest benefits result from otherwise fortifying the spring pocket and box beam. The frame rail box beam and spring pocket exert tremendous influence on steer angle behavior, and can increase roll stiffness and minimize camber change if properly reinforced.
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How to Work Race Tires on NASCAR Ovals (2000-01-3571)
Racing Chassis and Suspension Design, 1Co-Authors: Carroll SmithAbstract:Working NASCAR tires correctly will help a team qualify well and have a chance to win on Sunday. Aerodynamics, engines, and shocks are not the only things. Tire usage dictates Suspension Geometry, springs, weight jacking, and shock choices. Tire slip losses in corners are huge, over 1 00 HP in qualifying trim and over 150 HP in race trim. Proper tire usage reduces drag HP for qualifying and controls right side tire heating in race trim. Tire slip loss heats the tread rubber and is the primary factor limiting car performance on short tracks. Evaluation of several adjustments on tire and car cornering performance is determined using the Hallum Contact Patch Model presented in SAE 983028 Understanding Race Tires. One psi of tire pressure is significant to car performance. Tire and car performance changes with toe, Ackerman, camber, aerodynamic force, load jacking, and weight, are compared to the performance change with tire pressure. The Hallum Model considers heating so dynamic tire performance phenomena can be evaluated.
Daniele Dini - One of the best experts on this subject based on the ideXlab platform.
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Series Active Variable Geometry Suspension for Road Vehicles
IEEE ASME Transactions on Mechatronics, 2015Co-Authors: Carlos Arana, Simos A. Evangelou, Daniele DiniAbstract:A new family of electro-mechanical active Suspensions that offers significant advantages with respect to passive and semiactive Suspensions, while at the same time avoiding the main disadvantages of alternative active solutions, is presented in this paper. The series active variable Geometry Suspension takes a conventional independent passive or semiactive Suspension as its starting point, and improves its behavior by actively controlling the Suspension Geometry with an electro-mechanical actuator. The advantages of this type of Suspension are discussed and its simplest variant is studied in detail. Insight on the design process, as well as on the actuator modeling and selection is provided. Moreover, a control system for pitch attitude control of the chassis is presented. Simulation results obtained with a high-fidelity, full-vehicle, nonlinear model of a high-performance sports car that includes actuator dynamics and saturation limits are shown to confirm the potential of the proposed system.
Gregory P Herrick - One of the best experts on this subject based on the ideXlab platform.
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the effects of local spring perch flexibility on Suspension Geometry of a winston cup race car
SAE transactions, 1998Co-Authors: Lonny L Thompson, Gregory P HerrickAbstract:In order to achieve predictable handling of a race car, local mounts connecting Suspension components to the chassis should be sufficiently rigid to minimize unwanted local deflection which may adversely affect Suspension Geometry. In this work, the effects of local chassis flexibility of the spring perch on roll stiffness, tire camber change, and steer angle change are determined from a finite element model (FEM) of a Winston Cup race car. Details such as side gussets, supporting brackets, and local curvature of the frame rail spring pocket are included in a shell model of the spring perch. The local shell model of the spring perch is integrated with the global finite element stiffness model of the chassis and Suspension consisting of an assembly of beam and shell elements. A parametric study on the effects of thickness changes for seven different areas of the spring perch has been performed. Tire camber change, steer angle change, and chassis roll stiffness are plotted as a function of thickness variation for each of the seven perch areas. Results indicate that the surface with the most adverse affects on torsional stiffness, roll stiffness, and camber changes, resulting from reduced thickness, is the principal spring support plate. Stiffness increases may be achieved by increasing the thickness of the spring plate, spring pocket, and frame rail box beam, but the greatest benefits result from otherwise fortifying the spring pocket and box beam. The frame rail box beam and spring pocket exert tremendous influence on steer angle behavior, and can increase roll stiffness and minimize camber change if properly reinforced.
Carlos Arana - One of the best experts on this subject based on the ideXlab platform.
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Series Active Variable Geometry Suspension for Road Vehicles
IEEE ASME Transactions on Mechatronics, 2015Co-Authors: Carlos Arana, Simos A. Evangelou, Daniele DiniAbstract:A new family of electro-mechanical active Suspensions that offers significant advantages with respect to passive and semiactive Suspensions, while at the same time avoiding the main disadvantages of alternative active solutions, is presented in this paper. The series active variable Geometry Suspension takes a conventional independent passive or semiactive Suspension as its starting point, and improves its behavior by actively controlling the Suspension Geometry with an electro-mechanical actuator. The advantages of this type of Suspension are discussed and its simplest variant is studied in detail. Insight on the design process, as well as on the actuator modeling and selection is provided. Moreover, a control system for pitch attitude control of the chassis is presented. Simulation results obtained with a high-fidelity, full-vehicle, nonlinear model of a high-performance sports car that includes actuator dynamics and saturation limits are shown to confirm the potential of the proposed system.
Lonny L Thompson - One of the best experts on this subject based on the ideXlab platform.
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the effects of local spring perch flexibility on Suspension Geometry of a winston cup race car
SAE transactions, 1998Co-Authors: Lonny L Thompson, Gregory P HerrickAbstract:In order to achieve predictable handling of a race car, local mounts connecting Suspension components to the chassis should be sufficiently rigid to minimize unwanted local deflection which may adversely affect Suspension Geometry. In this work, the effects of local chassis flexibility of the spring perch on roll stiffness, tire camber change, and steer angle change are determined from a finite element model (FEM) of a Winston Cup race car. Details such as side gussets, supporting brackets, and local curvature of the frame rail spring pocket are included in a shell model of the spring perch. The local shell model of the spring perch is integrated with the global finite element stiffness model of the chassis and Suspension consisting of an assembly of beam and shell elements. A parametric study on the effects of thickness changes for seven different areas of the spring perch has been performed. Tire camber change, steer angle change, and chassis roll stiffness are plotted as a function of thickness variation for each of the seven perch areas. Results indicate that the surface with the most adverse affects on torsional stiffness, roll stiffness, and camber changes, resulting from reduced thickness, is the principal spring support plate. Stiffness increases may be achieved by increasing the thickness of the spring plate, spring pocket, and frame rail box beam, but the greatest benefits result from otherwise fortifying the spring pocket and box beam. The frame rail box beam and spring pocket exert tremendous influence on steer angle behavior, and can increase roll stiffness and minimize camber change if properly reinforced.
