Method and apparatus for constructing a complex tool surface for use in an age forming process

A method for constructing a complex tool surface for use in the age forming process comprising:

• a. Forming a geometrical representation of a panel;
• b. Forming a geometrical representation of a tool surface representing an age forming tool shape;
• c. Segmenting the geometrical representation of the entire work piece into individual panel elements;
• d. Segmenting the geometrical representation of the tool surface into individual tool elements;
• e. assigning a time hardening creep strain equation to each panel element;
• f. Reconfiguring the geometrical representation of the entire panel to match the geometrical representation of the tool surface;
• g. Assigning an induced stress to each individual element of the panel;
• h. Simulating the reconfigured panel's exposure to an elevated temperature environment to relax the induced stress on each individual element of the panel in accordance with the time hardening creep strain equation assigned to each panel element;
• i. Simulating releasing the constraints on the panel reconfigured to the shape of the age forming tool to produce a simulated panel shape;
• j. Comparing the simulated panel to a geometrical representation of a part to determine differences between the part and the panel;
• k. Modifying the geometrical representation of the tool to account for the differences between the part and the panel;
• l. Repeating steps a-k until the differences between the panel and the part fall within acceptable tolerances;
• and
• m. Constructing a tool in accordance with the modified geometrical representation of the tool.

Apparatus for constructing a complex tool surface for use in an age forming process, the apparatus comprising:

• a. A computer model of a flat panel representing a component where the part has been broken down into finite elements connected by a plurality of nodes;
• b. A computer model of a tool having a complex shape;
• c. A routine for assigning characteristics to all of the finite elements;
• d. Means for simulating the flat panel model constrained to the tool model in an age forming process to produce a simulated component;
• e. Means for adjusting the tool model in response to the differences between the component and the simulated component;
• and
• f. Means for constructing the tool in accordance with the adjusted tool model.