Material consolidation modeling and control system

• US 5,136,497 A
• Filed: 07/12/1990
• Issued: 08/04/1992
• Est. Priority Date: 07/12/1990
• Status: Expired due to Term

• Current Assignee: New BDM Incorporated, Northrop Grumman Systems Corporation (Northrop Grumman Corporation), United States Secretary of Commerce
• Original Assignee: BDM International, Inc. (Northrop Grumman Corporation)
• Inventors: O'Brien, David W., Parrish, Phillip A., Coe, Carlos J., Fields, Richard J., McMeeking, Robert M., Wadley, Hayden N. G., Henniges, Benjamin L., Aravas, Nikolaos, Godfrey, Elizabeth A., Payne, Jeffery E., Ashby, Michael F.
• Primary Examiner(s): CANGIALOSI, SALVATORE A
• Application Number:
  US07/551,313
• Time in Patent Office: 754 Days
• Field of Search: 364/149-156, 364/162, 364/164, 364/165, 364/477, 364/578
• US Class Current: 700/45
• CPC Class Codes: G05B 13/0205 not using a model or a simulator of the controlled system
• CPC Class Codes: G05B 17/02 electric

Abstract

A process and apparatus for providing simulation and modeling and control which permits user feedback for purposes of implementing design and process optimization for composite or powder compact materials. Control is achieved through a dual feedback and feedforward hierarchical control scheme employing an interactive modeling system for providing the feedforward control data and a PID control loop for the feedback control. Modeling is based upon constitutive equations which form the basis of modeling solutions derived from the micromechanical relationships inherent in the consolidated materials. The system is implemented in an FEM software platform such that a graphics based visualization in three dimensional form can be provided to the user.

Claims

1. An apparatus for controlling the consolidation of material forms, comprising:

modeling means to stimulate consolidation processes;

user-interface means for providing the system operator with visual and graphical representations of the output of said modeling means;

material consolidation control means wherein information provided to said modeling means through said user-interface means provides feedforward control information for said consolidation processes; and

PID control means for providing feedback control information to control said consolidation processes wherein both said feedforward control and feedback control processing occurs simultaneously.

2. The apparatus of claim 1 wherein said modeling means include:

relation means for receiving particular parameters for the material and consolidation process and for determining the constitutive relations which govern material behavior.

3. The apparatus of claim 2 wherein said constitutive relations are based on continuum mechanics.

4. The apparatus of claim 2 wherein said constitutive relations govern multiple densification mechanisms including plasticity, power-law creep and diffusion.

5. The apparatus of claim 4 wherein said relation means interrelate the constitutive relations governing the multiple densification mechanisms.

6. The apparatus of claim 5 wherein said relation means interrelate the constitutive relations based upon an estimate of a stage of densification of the material form.

7. The apparatus of claim 6 wherein said stage of densification is one of Stage I an Stage II.

8. The apparatus of claim 6 wherein said stage of densification is one of Stage I, Stage II and a transition between Stage I and Stage II.

9. The apparatus of claim 1 wherein the density of said material forms are in the range of 0.60 to 1.00.

10. The apparatus of claim 1 wherein the modeling means always provides convergent numerical solutions.

11. The apparatus of claim 1 wherein the user-interface means provides visual and graphical representations of one, two and three dimensional outputs.

12. The apparatus of claim 1 wherein the user-interface means provides representations of predicted macroscopic and microscopic shape changes.

13. The apparatus of claim 1 wherein the user-interface means provides representations of predicted physical instabilities of the material form.

14. The apparatus of claim 1 wherein the user-interface means provides representations of predicted effects of container surfaces and parameters on the consolidation of the material form.

15. The apparatus of claim 1 wherein the user-interface means provides representations of predicted densification on macroscope and microscopic bases.

16. The apparatus of claim 1 wherein the user-interface means include modifying means for allowing the user to change particular parameters for the material form and the consolidation process.

17. The apparatus of claim 1 further comprising measurement means for providing empirical parameters for the material form and consolidation process to said modeling means throughout said consolidation process.

18. The apparatus of claim 17 wherein said modeling means simulates said consolidation process based on the empirical parameters received from said measurement means.