Pneumatic tire designing method

Abstract

When a single performance or a plurality of antinomical performances are to be achieved, the best mode of a tire is designed under a given constraint condition. Each of blocks included in two pitch groups designated in a pitch array is modeled ( ), an objective function representing a tire performance evaluation physical amount, a constraint condition for restricting a tire shape, and a design variable which is an angle of a wall surface determining each of block shapes are determined ( ). Next, the design variable is varied continuously by r to determine a modified model ( to ). A value of the objective function of the modified model and a value of the constraint condition are calculated, and a sensitivity of the objective function and a sensitivity of the constraint condition are determined ( ). A variation amount of the design variable which minimizes a difference between block rigidities is estimated, a modified shape model is determined, the objective function is calculated, and by using a value of the design variable, a block shape of each of the pitch groups in the pitch array forming the tire is determined ( to ).