cai-aa/text-to-cae/abaqus-geometry

Abaqus Geometry Skill

Create parts, assemblies, and import CAD files for finite element analysis.

When to Use This Skill

Route here when user mentions:

• "create a box/beam/plate/bracket"
• "draw geometry", "make a cylinder/tube"
• "import STEP/IGES file"
• "extrude", "revolve", "create assembly"
• "position the parts", "build a component"

Route elsewhere:

• Meshing the geometry -> /abaqus-mesh
• Defining materials/sections -> /abaqus-material
• Applying loads or BCs -> /abaqus-load, /abaqus-bc
• Full analysis workflow -> /abaqus-static-analysis

Key Decisions

1. How to Create Geometry?

Decision guidance:

• Simple prismatic shape? -> Sketch + extrude
• Axisymmetric part? -> Sketch + revolve
• Existing CAD model? -> Import STEP file

2. Where to Place Origin?

3. Part vs Instance Coordinates

Important: After creating an instance, use instance.faces.findAt() not part.faces.findAt().

What to Ask User

If unclear, ask:

• Shape type? Box, cylinder, imported CAD?
• Dimensions? Length, width, height in mm
• Origin location? Corner or center?
• Import file available? Path to STEP/IGES?
• Features needed? Holes, fillets, chamfers?

Workflow

Step 1: Create Model and Part

Create the model container, then a 3D deformable part.

Step 2: Define Geometry

Choose approach based on shape:

• Sketch + Extrude: Draw 2D profile, extrude to 3D
• Sketch + Revolve: Draw profile, revolve around axis (360 degrees for full solid)
• CAD Import: Open STEP/IGES, create part from geometry file

Step 3: Add Features (Optional)

Add secondary features if needed:

• Cut holes using cut extrude
• Round edges with fillet
• Partition cells for BC/load regions

Step 4: Create Assembly Instance

Create root assembly with Cartesian datum, then create instance from part.

Step 5: Create Sets and Surfaces

Create named sets/surfaces on instance (not part) for:

• BC regions
• Load application surfaces
• Design regions (for optimization)

Finding Entities

Two methods to locate faces/edges:

1. findAt() - Exact coordinates (point must be ON the entity)
2. getByBoundingBox() - Tolerant box search (better for automation)

Combine multiple entities with + operator.

Common Pitfalls

Validation Checklist

Before proceeding to mesh/analysis:

• [ ] Part created with correct dimensions
• [ ] Geometry is watertight (no gaps)
• [ ] Instance created in assembly
• [ ] Sets created on instance for BC/load regions
• [ ] Partitions added if needed for region selection

Units

All dimensions use consistent units (mm-tonne-s-N-MPa):

• Length: mm
• Coordinates: mm

Code Patterns

For API syntax and code examples, see:

• API Quick Reference
• Common Patterns
• Troubleshooting Guide