Cornering force and aligning torque relative to slip angle were measured by using Flat Trac for two tire samples which were used in vehicle on-center steering measurement.
However Tire B shows higher aligning torque by 9~25% up to 4[degrees] slip angle than Tire A.
The case that aligning torque in lower slip angle is higher than Tire A was not been tested in this measurement.
It is necessary to understand how tire design parameters have an effect on aligning torque stiffness to control on-center steering response during tire development.
In order to study the effect of structural design parameters on aligning stiffness, the base FE model was built by using Min design parameters in Table 1 at first.
Cornering force and aligning torque at each slip angle were calculated.
Figure 4 shows the cornering force and aligning torque at 1[degrees] slip angle calculated in FE analysis for six tire models.
In order to study the influence of tire tread pattern on aligning stiffness, three kinds of tread shape were modeled based on the slick (non-patterned) tire with tire size 215/55R17 through hand carving.
Then cornering force and aligning torque relative to slip angle for three tire samples shown in Table 2 were measured by using Flat Trac.
In order to study the effect of tread viscoelastic property on aligning stiffness, two kinds of tire samples (Tire F and Tire G) with different tread compound were built by using same summer tread pattern mold and applying same inner structure.
Then F&M for Tire F and Tire G was measured and Table 5 shows cornering force and aligning torque in 100% load condition.
Previous parameter study shows influence of tire design parameters on aligning torque at lower slip angles related to on-center steering performance and cornering stiffness related to handling performance.
Then cornering force and aligning torque relative to slip angle for four tire samples shown in Table 6 were measured by using Flat Trac.