Efficient simulation of manufacturing process of shapeable material using finite element analysis

• US 7,664,623 B1
• Filed: 11/10/2006
• Issued: 02/16/2010
• Est. Priority Date: 11/10/2006
• Status: Active Grant

• Current Assignee: Ansys Incorporated
• Original Assignee: Livermore Software Technology Corporation
• Inventors: Hallquist, John
• Primary Examiner(s): FREJD, RUSSELL WARREN
• Application Number:
  US11/558,752
• Time in Patent Office: 1,194 Days
• Field of Search: 703/2, 703/6, 700 95- 97, 700/117, 700/132
• US Class Current: 703/2
• CPC Class Codes: G06F 2119/18 Manufacturability analysis or optimisation for manufacturability
• CPC Class Codes: G06F 30/23 using finite element methods [FEM] or finite difference methods [FDM]
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

Shapeable materials of interest are modeled with a rectangular mesh having N columns and M rows of substantially similar shell elements. The shapeable materials of interest are held in tension between a sink and a source. A column of fictitious elements is added to make the mesh wrapped-around continuous. The fictitious elements are marked as inactive, while other elements are marked as active. As the simulation moves on, the active elements are marched in the product producing direction of the machinery. When a pre-defined distance has traveled in the simulation the present invention performs the following:

• • Activate inactive elements at the source;
  • Copy all history data including stresses from the last column of active elements to newly activated elements;
  • Deactivate the lead column of active elements at the sink; and
  • Move the set of nodal boundary conditions to newly established boundary nodes at the sink and the source.

Claims

1. A method of simulating a manufacturing process of shapeable materials using a finite element analysis (FEA), the method comprising:

(a) receiving, in a computer having a FEA application module installed thereon, definitions of the machinery and the shapeable materials to be manufactured in the machinery;

(b) creating a FEA model representing the shapeable materials, the FEA model contains a rectangular mesh having N columns and M rows of substantially similar sized active shell elements, wherein the rectangular mesh represents a particular section of the shapeable materials of interest in the machinery;

(c) defining a sink and a source as respective boundaries of the rectangular mesh;

(d) creating a column of inactive shell elements to connect the sink and the source such that the rectangular mesh becomes a continuously looping mesh;

(e) updating a simulation time and calculating a solution at the simulation time in the FEA;

(f) when said particular section in said simulating of the manufacturing process has traveled more than a pre-defined distance in the FEA, performing an element rotation operation between the active and the inactive shell elements at the sink and the source; and

(g) repeating (e)-(f) until the solution of the FEA has reached a steady state showing a result of said simulating the manufacturing process to be used for assisting a user to make a decision in improvement of the manufacturing process.

2. The method of claim 1, wherein the shapeable materials may include, but not be limited to, paper, fabric, and sheet metal.

3. The method of claim 1, wherein N and M are positive integers.

4. The method of claim 1, wherein the shell elements are quadrilateral or triangular element.

5. The method of claim 1, wherein the particular section of the shapeable materials of interest is held in tension between the sink and the source.

6. The method of claim 5, wherein the tension is represented by a set of nodal boundary conditions applied at the sink and the source in the finite element analysis.

7. The method of claim 1, wherein the inactive shell elements are not included in the solution of the finite element analysis.

8. The method of claim 1, wherein the pre-defined distance is

substantially equal to the averaged length of all of the active shell elements between the sink and the source.

9. The method of claim 1, wherein the pre-defined distance is equal to 95% of the averaged length of all of the active shell elements.

10. The method of claim 6, said performing the element rotation operation further comprising:

activating the inactive shell elements at the source;

copying all history data from the last column of active elements to the newly activated elements;

deactivating the lead column of the active elements at the sink so that the lead column becomes inactive; and

moving the set of nodal boundary conditions to newly established boundary nodes at the sink and the source.

11. The method of claim 10, wherein the history data includes element stresses data.

12. A computer recordable storage medium having computer readable code embodied in the medium for causing an application module to execute on a computer for simulating manufacturing process of shapeable materials using a finite element analysis (FEA) by a method comprising:

(a) receiving definitions of the machinery and the shapeable materials to be manufactured in the machinery;

(b) creating a FEA model representing the shapeable materials, the FEA model contains a rectangular mesh having N columns and M rows of substantially similar sized active shell elements, wherein the rectangular mesh represents a particular section of the shapeable materials of interest in the machinery;

(c) defining a sink and a source as respective boundaries of the rectangular mesh;

(d) creating a column of inactive shell elements to connect the sink and the source such that the rectangular mesh becomes a continuously looping mesh;

(e) updating a simulation time and calculating a solution at the simulation time in the FEA;

(f) when said particular section in said simulating of the manufacturing process has traveled more than a pre-defined distance in the FEA, performing an element rotation operation between the active and the inactive shell elements at the sink and the source; and

(g) repeating (e)-(f) until the solution of the FEA has reached a steady state showing a result of said simulating the manufacturing process to be used for assisting a user to make a decision in improvement of the manufacturing process.

13. The computer recordable storage medium of claim 12, wherein the shapeable materials of interest are held in tension between the sink and the source.

14. The computer recordable storage medium of claim 13, wherein the tension is represented by a set of nodal boundary conditions applied at the sink and the source in the finite element analysis.

15. The computer recordable storage medium of claim 12, said performing the element rotation operation further comprising:

activating the inactive shell elements at the source;

copying all history data from the last column of active elements to newly activated elements;

deactivating the lead column of the active elements at the sink so that the lead column becomes inactive; and

moving the set of nodal boundary conditions to the newly established boundary nodes at the sink and the source.

16. A system for simulating manufacturing process of shapeable materials using a finite element analysis (FEA), the system comprising:

an I/O interface;

a communication interface;

a secondary memory;

a main memory for storing computer readable code for an application module;

at least one processor coupled to the main memory, the secondary memory, the I/O interface, and the communication interface, said at least one processor executing the computer readable code in the main memory to cause the application module to perform operations of;

(a) receiving definitions of the machinery and the shapeable materials to be manufactured in the machinery;

(b) creating a FEA model representing the shapeable materials, the FEA model contains a rectangular mesh having N columns and M rows of substantially similar sized active shell elements, wherein the rectangular mesh represents a particular section of the shapeable materials of interest in the machinery;

(c) defining a sink and a source as respective boundaries of the rectangular mesh;

(d) creating a column of inactive shell elements to connect the sink and the source such that the rectangular mesh becomes a continuously looping mesh;

(e) updating a simulation time and calculating a solution at the simulation time in the FEA;

(g) when said particular section in said simulating of the manufacturing process has traveled more than a pre-defined distance in the FEA, performing an element rotation operation between the active and the inactive shell elements at the sink and the source; and

(g) repeating (e)-(f) until the solution of the FEA has reached a steady state showing a result of said simulating the manufacturing process to be used for assisting a user to make a decision in improvement of the manufacturing process.

17. The system of claim 16, wherein the particular section of the shapeable materials of interest is held in tension between the sink and the source.

18. The system of claim 17, wherein the tension is represented by a set of nodal boundary conditions applied at the sink and the source in the finite element analysis.

19. The system of claim 16, said performing the element rotation operation further comprising operations of:

activating the inactive shell elements at the source;

copying all history data from the last column of active elements to the newly activated elements;

deactivating the lead column of the active elements at the sink so that the lead column becomes inactive; and

moving the set of nodal boundary conditions to newly established boundary nodes at the sink and the source.

20. The system of claim 19, wherein the active shell elements are included in said simulating of the manufacturing process, while the inactive shell elements are excluded.