Method, device, and program of designing press forming die, and method of manufacturing press formed part

A manufacturing method of a press forming die, comprising:

• a die model making step of making a die model in which a surface of the press forming die is provided with a virtual thickness by a nonrigid two-dimensional element;
• a die model stiffness distribution setting step of setting stiffness distributions of the die model by making a boundary condition of the two-dimensional element vary depending on a portion of the die model;
• a press forming load acquiring step of acquiring a press forming load by performing a press forming analysis by using the die model in which the stiffness distributions are set;
• a press forming load determining step of determining whether the press forming load is within a predetermined range of the press forming load;
• and
• a press forming die design stiffness determining step of
• determining the set stiffness distributions of the die model as design stiffness distributions of the press forming die in a case where it is determined in the press forming load determining step that the press forming load is within the predetermined range of the press forming load;
• and
• changing the stiffness distributions of the die model in the die model stiffness distribution setting step and repeating the press forming load acquiring step and the press forming load determining step until the press forming load falls within the predetermined range of the press forming load in a case where it is determined in the press forming load determining step that the predetermined range of the press forming load is not within the predetermined range of the press forming load, and determining the changed stiffness distributions of the die model as the design stiffness distributions of the press forming die when the press forming load falls within the predetermined range of the press forming load;
• and
• a press forming die design stiffness distributions acquiring step of acquiring the design stiffness distributions of a press forming die;
• a press forming die manufacturing step of manufacturing a real press-forming die based on the acquired design stiffness distributions of the press forming die;
• and
• a press forming step of performing press forming by using the real press-forming die.