Abstract
The tires which are contacted on the road directly are important parts to determine the vehicle behavior. Therefore neglecting defects of tire or information through the tire from the road is the one of main reasons of causing the traffic accidents. In that reason recently the intelligent tire system project named “Apollo project” was started from EU which aims to improve control performance by detecting the strains of tire using the tire sensors. However the tire sensors are not sufficient to measure the strains yet, because of adhesion problem from the difference of stiffness between the tire and sensor and hysteresis of tire. In this research, using FE analysis we estimated the strains which located on the tire sensors and discovered the relations between the strains and driving conditions. Our target tire is 235/65/R17 size for SUV. At first, we performed analyzing of cross-section of target tire and from the result the tire FE model which consists of 8 parts including the ground is generated by IDEAS program. The FE analysis is accomplished using the ABAQUS Standard program. The tire model is constructed as axisymmetric model and analyzed with steady state rolling conditions. Afterward, convergence characteristic of The FE model has to be checked and validation test also has to be performed. The convergence test determined tire model consisted of 40080 nodes and 39600 elements. And the validation test is performed by comparing the vertical stiffness to verify the tire FE model. In the result, the FE model is achieved fewer than 10% error. The Tire strain data were calculated in 3 positions where sensors will be attached in two directions (lateral and circumferential directions). According to the results, increasing the vertical loading causes the larger contact patch length and the speed of tire increases the strains of whole tire elements. And other values (slip ratio, slip angle, camber angle) are predictable from analyzing the changes of strains. Therefore it can be possible to approximate the driving conditions from the tire strain data when the intelligent tire system is developed. In the future, we will make the standardized shape of tire strain and the parameters which determine the strain tendency. And then we plan to build the numerical tire strain model which is for simulations of intelligent tire system. From this research, we estimated the tire strain when tire is rolling and made the data-base to build the numerical tire strain model to develop the intelligent tire system.
Keywords: Intelligent tire system, tire strain model, tire FE model, numerical tire model