Finite Element Investigation On Wet-road Braking Performance Of Radial Tire

When the vehicle is running on the wet-road with a high speed, the tire tractionefficiency decreases due to the hydrodynamic force caused by the water which flow in the tiretread grooves. The contact force and adhesion coefficient between tire and road surface alsodecrease due to the hydrodynamic force. Therefore, how to improve the braking performanceon the wet-road of tires is important for tire design. Because the tire braking process on thewet-road associates with impacting and large deformation, and the interaction between tireand water involves complex fluid-structure coupling problem, implicit FEM is difficult todeal with this issue. In an early stage, the test is mainly performed to analyze and evaluate thetire braking performance. With the development of numerical techniques and computationfacilities recently, it is possible to study the influence of tires’ tread pattern and materials onbraking performance using FEM.Base on205/55R16half steel tire, using Yeoh constitutive and rebar model to simulaterubber and cord-rubber composite materials respectively. With the efforts of improving theefficiency, discrete rigid elements sharing the same nodes with bead outer were used tosimulate the rim. Considering the operation of ABS and the fluid-structure interactionbetween the tire and water, the tire braking performance on the wet-road was simulated byusing the commercial FEM codes-ABAQUS with a braking process discretized analysismethod raised by J.R.Cho in South Korea’s Pusan National University.Firstly, a FE braking model of longitudinal grooved radial tire on the wet-road with10mm depth was studied. The comparison with the simulation results of braking performancebetween dry-road and wet-road indicated that the tire braking distance on wet-road was muchlarger than on dry-road, and the validity of the method was preliminarily validated.Then, the influence of tire braking distance on wet-road with1.5mm depth withdifferent complex pattern and tread materials was studied by FEM. The simulation resultswere consistent with the corresponding test which shows the simulation method accuracy wasfurther confirmed. The results show that changing the complex tread pattern had a littleinfluence to the tire braking performance, while the tread material had a significant influence.