| 摘要 |
PROBLEM TO BE SOLVED: To provide a method that derives an optimal shape of the wall surface in a three-dimensional sipe.SOLUTION: A three-dimensional sipe wall surface shape deriving method includes the steps of: setting a portion except a tread side end part among sipe wall surfaces 13a in a design area Ar; calculating a contact pressure value Pexpressed by the engagement between a pair of sipe wall surfaces under the pre-set constrained conditions every node point by the finite element analysis; determining whether or not an evaluation function value Pcorresponding to a contact pressure value acting on the whole design area Ar becomes higher than a predetermined target threshold value th; correcting a sipe wall surface shape when not satisfying conditions; and repeating the finite element analysis by the block model 1 after the correction until satisfying the conditions. A node point of the contact pressure value Phigher than an average contact pressure value Pamong the design areas Ar is extracted, and the extracted node point and a facing node point are changed in position to the outside L1 in the normal line direction of the sipe wall surface. Also, a node point of the contact pressure value Plower than the average contact pressure value Pis extracted, and the extracted node point and the facing node point are changed in position to the inner side L2 in the normal line direction of the sipe wall surface. |
