Importing Your Geometry & Meshes

Bring what you already have — CAD, meshes from other tools, CFD pressure maps — instead of rebuilding.

1. What can I import?

Format	What it is	How to import
Abaqus .inp	mesh + sets from Abaqus/CalculiX workflows	Import → Abaqus INP
NASTRAN .bdf/.dat	classic aerospace mesh format	Import → NASTRAN BDF
Gmsh .msh	open-source mesher output (tets)	Import → GMSH MSH
STL	surface triangles from any CAD tool	Import → STL (converted to tet volume mesh via Delaunay)
Universal .unv	I-DEAS/Simcenter neutral mesh	Import → UNV
CAD step/iges	solid geometry	Import → CAD (tessellates, then tets)
CFD pressure map	pressures on faces from a flow solve	Import → CFD pressure (see [Multiphysics](multiphysics.md))
Image → geometry	sketch/photo traced to profile	Tools → Image to Geometry

Scripting surface: model.importInp runs the Abaqus import headlessly (Agent Dock protocol).

2. When do I use it?

Use when	Don't use for
You have existing CAD or mesh files	Creating geometry from scratch (use Design tab)
Importing from other FEA tools	Simple models (use built-in primitives)
Collaborating with external teams	Quick checks (use templates)

Use cases

Problem Type	Industry	Example
Model translation	Aerospace	CATIA → FEA mesh
Legacy model reuse	Automotive	Old NASTRAN model import
External mesh import	Research	GMSH mesh with physical groups
CFD pressure mapping	Aerospace/Automotive	Wind load on panel
Additive manufacturing	Medical	Patient-specific implant mesh
Multi-tool workflow	Energy	CAD → mesh → solve in FEA Lab

Step 1 — Inspect (Design step)

Rotate the model; check the element count and that units are what you think. mm vs m is the classic silent killer — FEA Lab's material library flags densities outside physical ranges (e.g. ρ = 7.85e-9 in tonne/mm³ convention gets a warning, not a silent solve).

Step 2 — Assign materials

If the import didn't carry them: Boundary page → Library tab → assign real materials with yield strength so you can get verdicts.

Step 3 — Check the mesh quality gate

Mesh step: distorted or degenerate cells are flagged with locations. Refine or remesh those regions before solving — imported meshes carry someone else's decisions.

Step 4 — Continue as native

From here every domain flow applies unchanged: [static](static-structural.md), [dynamics](dynamics.md), [thermal](thermal.md), etc.

3. Reading results honestly

Imported meshes carry someone else's decisions: check for sliver

elements at curved boundaries before trusting local stresses.

STL→tet conversion is for solid parts; thin-walled CAD should be

shelled/midsurfaced by you first, else you get huge uniform tets that miss bending stiffness.

Unit discipline: FEA Lab's default convention is mm-N-MPa in examples;

imported SI files (m-Pa) work but never mix.

4. Boundaries of truth

Check	Reference	Our error
Distributed body/pressure loads on imported meshes	reference nodal equivalents	validated (test_element_loads_reference)
CFD pressure mapping	sample distinctness through pipeline	all values preserved
Delaunay tet quality on closed STL	positive-volume cells	gate enforced

Not covered: geometry healing/defeaturing, mid-surface extraction, parameterized CAD edits.

Open the interactive workspace — mesh, solve, validate and export in the browser.

Start a guided solve