Patent ID: 7031892

Claim:
A computer-implemented numerical-simulation method for rotary metal forming, comprising: dividing, into a plurality of finite elements, a predetermined model zone between two imaginary cutting planes intersecting with a circumferential direction in a rotary formed body rotated about an axis of rotation; setting velocity boundary conditions of said imaginary cutting planes for said predetermined model zone by a function, wherein an angular velocity for rotation about said axis of rotation of said rotary formed body is variable and the velocity boundary conditions are set so as to model plastic deformation of said rotary formed body in the circumferential direction; and analyzing, by a finite element method, a forming process that continuously produces plastic deformation by localized contact with said rotary formed body, wherein in a case where said axis of rotation is displaced with an addition of an increase in diameter of said rotary formed body in said forming process, said velocity boundary conditions are set equal to a function having three variables, including (1) a rate of increase of the diameter of said rotary formed body, (2) said angular velocity for rotation about said axis of rotation of said rotary formed body, and (3) a correction value for traverse velocity of said axis of rotation.