Method of estimating tire performance

A fluid simulation comprising the steps of:

• (a) determining a tire model having a pattern configuration to which deformation can be imparted by at least one of ground contacting and rolling, and determining a fluid model which is partially or wholly filled with a fluid and which comes into contact with at least a portion of the tire model;
• (b) executing a deformation calculation of the tire model;
• (c) executing a fluid calculation of the fluid model;
• and
• (d) identifying a boundary surface between the tire model after the deformation calculation in step (b) and the fluid model after the fluid calculation in step (c), imparting a boundary condition concerning the identified boundary surface to the tire model and the fluid model, and performing the deformation calculation and the fluid calculation until the fluid model assumes a state of pseudo flow.

A method of designing a pneumatic tire, comprising the steps of:

• (1) determining a plurality of tire models each having a pattern configuration to which deformation can be imparted by at least one of ground contacting and rolling, and determining a fluid model which is partially or wholly filled with a fluid and which comes into contact with at least a portion of a tire model;
• (2) executing a deformation calculation of each of the tire models;
• (3) executing a fluid calculation of the fluid model;
• (4) identifying a boundary surface between the tire models after the deformation calculation in step (2) and the fluid model after the fluid calculation in step (3), imparting a boundary condition concerning the identified boundary surface to the tire models and the fluid model, and performing the deformation calculation and the fluid calculation until the fluid model assumes a state of pseudo flow;
• (5) determining a physical quantity occurring in at least one of the tire models and the fluid model in step (3) or step (4);
• (6) estimating a plurality of tire performances on the basis of the physical quantity;
• and
• (7) designing a tire on the basis of a tire model having a tire performance selected from the plurality of tire performances.

A method of designing a vulcanizing mold for a tire, comprising the steps of:

• (α) determining a plurality of tire models having a pattern configuration to which deformation can be imparted by at least one of ground contacting and rolling, and determining a fluid model which is partially or wholly filled with a fluid and which comes into contact with at least a portion of the tire models;
• (β) executing a deformation calculation of each of the tire models;
• (γ) executing a fluid calculation of the fluid model;
• (δ) identifying a boundary surface between the tire models after the deformation calculation in step (β) and the fluid model after the fluid calculation in step (γ), imparting a boundary condition concerning the identified boundary surface to the tire models and the fluid model, and performing the deformation calculation and the fluid calculation until the fluid model assumes a state of pseudo flow;
• (ε) determining a physical quantity occurring in at least one of the tire model and the fluid models in step (γ) or step (δ);
• (ζ) estimating a plurality of tire performances of each of the tire models on the basis of the physical quantity;
• and
• (η) designing the vulcanizing mold for the tire on the basis of one of the tire models having a tire performance selected from the plurality of tire performances.

A method of manufacturing a pneumatic tire, comprising the steps of:

• (I) determining a plurality of tire models each having a pattern configuration to which deformation can be imparted by at least one of ground contacting and rolling, and determining a fluid model which is partially or wholly filled with a fluid and contacts at least a portion of the tire models;
• (II) executing a deformation calculation of each of the tire models;
• (III) executing a fluid calculation of the fluid model;
• (IV) identifying a boundary surface between each of the tire models after the deformation calculation in step (II) and the fluid model after the fluid calculation in step (III), imparting a boundary condition concerning the identified boundary surface to each of the tire models and the fluid model, and performing the deformation calculation and the fluid calculation until the fluid model assumes a state of pseudo flow;
• (V) determining a physical quantity occurring in at least one of the respective tire models and the fluid model for each of the tire models in step (III) or step (IV);
• (VI) estimating a plurality of tire performances, each tire performance being estimated for each of the tire models on the basis of the physical quantity;
• and
• (VII) manufacturing the tire on the basis of a tire model having a tire performance selected from the plurality of tire performances.

A recording medium with a tire-performance estimation program recorded thereon for estimating a tire performance by a computer, comprising the steps of:

• (A) determining a tire model having a pattern configuration to which deformation can be imparted by at least one of ground contacting and rolling, and determining a fluid model which is partially or wholly filled with a fluid and which comes into contact with at least a portion of the tire model;
• (B) executing a deformation calculation of the tire model;
• (C) executing a fluid calculation of the fluid model;
• and
• (D) identifying a boundary surface between the tire model after the deformation calculation in step (B) and the fluid model after the fluid calculation in step (C), imparting a boundary condition concerning the identified boundary surface to the tire model and the fluid model, and performing the deformation calculation and the fluid calculation until the fluid model assumes a state of pseudo flow.

A method of designing a pneumatic tire, comprising the steps of:

• (11) determining a tire model which includes at least a cross-sectional shape of a tire, including an internal structure, and which has a pattern configuration to which deformation can be imparted by at least one of ground contacting and rolling, determining a fluid model which is partially or wholly filled with a fluid and which comes into contact with at least a portion of the tire model, determining an objective function representing a physical quantity that evaluates tire performance, a design variable that evaluates a cross-sectional shape of the tire, a tire structure, or a pattern configuration, and determining a constraint that constrains at least one of the cross-sectional shape of the tire, the tire structure, the pattern configuration, the physical quantity that evaluates performance, and a tire size;
• (12) estimating the tire performance on the basis of the physical quantity occurring in at least one of the tire model and the fluid model in at least one of a state of deformation of the tire model and a state of pseudo flow of the fluid model;
• (13) determining a value of the design variable which gives an optimum value of the objective function while satisfying the estimated tire performance and the constraint;
• and
• (14) designing the tire on the basis of the design variable which gives the optimum value of the objective function.

An optimization analyzer comprising:

• an estimator that estimates a performance of a tire from a design parameter of the tire;
• a transformation-system computer that determines a nonlinear relationship of correspondence between the design parameter of the tire and the performance of the tire;
• an input device that determines an objective function representing the tire performance, determines a constraint that constrains an allowable range of at least one of the tire performance and a manufacturing condition of the tire, and inputs the objective function and the constraint as items of optimization;
• and
• an optimization calculator that determines the design parameter of the tire which gives an optimum value of the objective function on the basis of the items of optimization inputted by said input means by using said transformation-system computer.

A recording medium with a tire optimization analysis program recorded thereon for designing a tire by a computer, wherein the optimization analysis program is arranged to:

• estimate a performance of the tire from a design parameter of the tire;
• determine a nonlinear relationship of correspondence between a design parameter of the tire and the performance of the tire;
• determine an objective function representing the performance of the tire, determine a constraint that constrains an allowable range of at least one of the performance of the tire and a manufacturing condition of the tire;
• and
• determine the design parmeter of the tire which gives an optimum value of the objective function based on the determined relationship of correspondence, the objective function, and the constraint, and design the tire on the basis of the design parameter of the tire.