| Automobile as an important vehicle has been widely used in the modern society, which will be driven on water or wet toads unavoidably. The car tire at high speed would occur hydroplaning. When this phenomenon happens, the coefficient of friction between tire and road surface will dropped significantly, especially the speed exceed the limited velocity, the dynamic pressure of water could make tire totally loss the driving force and braking force. This will directly threat to the life safety of passengers and drivers. So the driving velocity analysis of the car on the wet pavement is one of the most important parts in the performance analysis. But due to the complex structure and the nonlinear property material, the large quantity of modeling works brings so much trouble for the structure and performance analysis. In order to achieve the high efficiency and automation, the tire finite element modeling should not only include the structure dimension on the geometrical concept and the performance index of the composite, but also include some techniques such as the boundary conditions, load parameterization, mechanic modeling.A finite element model of radial tire which type is195/60R14at60series was built by MSC.Dyrtan, which is a large finite element analysis procedure, using the Lagrange FEM to solve the solid model, the Euler FVM to solve the fluid model, the General Coupling algorithm to dealing with their interaction. According to different tread pattern of tire, the tire deformation and contact pressure on wet pavement is analysis deeply and systematic in this paper.The radial three-dimensional finite element model is presented in this paper. Combined with Lagrange method and Euler method, the General Coupling algorithm is established for the tire hydroplaning analysis. The tire orthotropic material parameters are given by mechanics formulation which is commonly used in composite. Meanwhile the establishment of three different forms tread pattern of the tire can contrastive analysis the properties of rolling and hydroplaning, which is provided the calculation basis for the below paper.The tire property of grounding under static loading condition is analyzed. Through the analysis of the tire on horizontal ground and slope ground, the basic law which is the influence of the slope angle to the tire grade ability is presented preliminarily. The tire critical velocity on slope ground is estimated through the diagram of the contact force change progress with the increased velocity on different slope pavements. On this basis, the contact patch and force of the rolling tire is analyzed in-depth, the contact patch distribution of different form tire patterns is analyzed contrastively, the contact force change of different form tire patterns is given. Among the contact patch distribution and the contact force change have a certain theoretic meaning and guiding to continue to further analysis.It is the focus of this paper that the hydroplaning property of the radical tire is reached apply the Fluid-structure interaction principle. After fully studying the interaction between the radical tire and water on wet pavement, the change progress of contact force with the increased velocity on dry-wet pavement is contrasted. Result shows that the critical velocity on wet pavement is much less than it on dry pavement. And according to the fluid mechanics theory, it is obtained the interaction formula between the hydroplaning critical velocity and load. Finally through analyzing the relationship between the pressure of water and adhesive force, we can reach a conclusion that compared with S type pattern and strip type pattern, the critical velocity of V type pattern tire is the maximum. These conclusions have an important role for the structure design of the tire with complex pattern. |
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