Source model preparation
For SIEMENS NX™ users

SIEMENS NX™ can be used to create a numerical FEA model, which can be exported into the DAT format to get a suitable source model for ProTOp. The DAT output generated by SIEMENS NX™ supports:

• multiple load cases and
• fictive surface loads

Multiple load cases can be defined by defining multiple subcases. Note that ProTOp will import each subcase as a separate load case for the optimization procedure.

Source model preparation outline

To prepare a ProTOp usable FEA model with SIEMENS NX™, the procedure is roughly the same as preparing a usual FEA simulation model. More precisely, the following steps should done:

• Create a CAD model (generate geometric model and volume regions; Part Modeling module)
• Create a FEM model (define and assign materials, create mesh, connect separated bodies; FEM module)
• Create a simulation with correct options as described below (define loads, boundary conditions and subcases, and export a DAT file; SIM module)

IMPORTANT. When creating a solution, care must be taken to select the proper option. More precisely, in the Solution dialog the Solution type: SOL 101 Linear statics – Subcase Constraints has to be chosen. This option enables one or more load cases per solution which is crucial for an optimization task.

NOTE. The option Solution type: SOL 101 Linear statics – Subcase Constraints must be chosen regardless of what kind of optimization is planned: either static stiffness or modal eigenfrequency maximization. The actual type of maximization is always defined within ProTOp.

When SIEMENS NX™ is used to get the source model, pay attention to the limitations of the corresponding importer.

Limitations of the importer

The following options are supported by ProTOp when importing from DAT files created by SIEMENS NX™ software.

Part

• Single 3D Deformable Multi Solid Body

Connections

• Component contacts
  • Bonded, Global contact, Compatible mesh

Property

• Material
  • Linear Elastic Isotropic
  • Density, Uniform Distribution
• Material Assignment
  • Solid Body

Load

• External Loads
  • Force
  • Torque
  • Pressure
  • Gravity
  • Centrifugal Force
  • Temperature
• Fixtures
  • Fixed Constraint
  • Fixed Translation Constraint
  • Simply Supported Constraint
  • Pinned Constraint
  • Cylindrical Constraint
  • Slider Constraint
  • Roller Constraint
  • Symmetric Constraint
  • Anti-Symmetric Constraint

Mesh

• 3D Stress Family
  • 4-node (linear) tetrahedron
  • 10-node (quadratic) tetrahedron