OS-T: 1120 Linear Static Analysis using User-Defined Structural Material (MATUSR)

This tutorial demonstrates how to use the MATUSR user-defined material for linear static analysis for solid (Phase 1) and shell (Phase 2) elements.

The design takes a two-phased approach:
Phase 1: Solid Cylinder
Linear static analysis on a solid cylinder under tension (force of 10 N with the other end clamped)
Phase 2: Shell Flat Plate
Linear static analysis on a shell flat plate under tension (force of 10 N with the other end clamped)
The MATUSR Bulk Data Entry provides access to two subroutines:
usermaterial subroutine
Only used for Large Displacement Nonlinear analysis.
smatusr subroutine
Only used for Linear Static or Small Displacement Nonlinear analysis.

Both subroutines should be present for any problem regardless of the analysis type during compilation. However, only the corresponding subroutine will be used by OptiStruct for the analysis depending on the analysis type.

In this example, you will have both subroutines in the code during compilation; however, since you are running Linear Static analysis, only the smatusr subroutine will be used by OptiStruct.

The objective is to create linear static models for shell and solid models which run using MATUSR.

Figure 1. (a) Solid cylinder model under tension; (b) Shell flat plate model under tension
The following exercises are included:
  • Assign the material using MATUSR Bulk Data Entry.
  • Write a smatusr subroutine for the problem in Fortran (even though only the smatusr subroutine is used in the user material definition, you need to include the usermaterial subroutine, as well when generating the DLL).
  • Export a dynamic linked library and use it in the analysis using LOADLIB card.
  • Create and apply the linear static boundary conditions.
  • Submit the job to OptiStruct.
  • Post-process the results in HyperView