git:20260501.65fb77f to git:20260506.d521bcc

---

name: abaqus-sim

description: Use when driving Dassault Systemes SIMULIA Abaqus via input decks (.inp), Abaqus/CAE Python scripts, or iterative CAE authoring sessions for modeling, debugging, and reporting.

---

# abaqus-sim

This file is the **Abaqus** index. Use sim-cli for solver execution and live

CAE authoring; use portable Python text parsing for completed text artifacts

when the job files are already on disk.

Abaqus is a commercial finite element analysis (FEA) solver by Dassault

Systemes SIMULIA. The sim plugin supports two execution styles:

1. **Batch execution** for complete `.inp` decks or Abaqus/CAE Python files.

2. **CAE authoring sessions** for iterative model creation, inspection,

debugging, job submission, and report preparation. The default backend is

file-backed; the optional bridge backend keeps one noGUI CAE process alive

for faster agent loops.

It supports two script formats:

- **Input decks** (`.inp`) — keyword-driven text files defining geometry,

materials, loads, BCs, and analysis steps

- **Abaqus/CAE Python scripts** (`.py`) — Python scripts using the

`abaqus` and `abaqusConstants` modules for parametric model building

The driver runs these via subprocess (`abaqus job=X input=file.inp

interactive` or `abaqus cae noGUI=script.py`). In CAE authoring sessions,

each `sim exec` snippet runs inside Abaqus/CAE against a saved session `.cae`

database, then saves the database back for the next step. With

`--backend bridge`, snippets are sent to one long-lived noGUI CAE process over

a localhost command channel protected by a per-session token. Use bridge mode

only in trusted workspaces owned by the session user. No Abaqus Python module

is imported into the sim process.

This is **not** the Ansys Mechanical plugin. Do not route Abaqus `.inp`

decks or Abaqus/CAE Python scripts through `solver=mechanical`; use

`solver=abaqus` for Abaqus execution/authoring and `solver=mechanical` only

for PyMechanical / Ansys Mechanical sessions.

---

## base/ — always relevant

| Path | What's there |

|---|---|

| `base/reference/input_deck_reference.md` | `.inp` file format: keyword syntax, node/element definitions, material, steps, BCs, output requests. |

| `base/reference/abaqus_scripting.md` | Abaqus/CAE Python scripting: `mdb`, `Part`, `Material`, `Step`, `Load`, `Job` objects. |

| `base/reference/doc_lookup.md` | How to check installed/official Abaqus docs, command help, fetched examples, and runtime API probes before guessing syntax. |

| `base/reference/authoring_workflow.md` | Agent workflow for iterative CAE modeling with `connect`, `exec`, `inspect`, and saved `.cae` state. |

| `base/reference/debug_reporting.md` | Debug loop and report checklist for `.msg`, `.sta`, `.dat`, ODB-derived results, assumptions, and acceptance criteria. |

| `base/reference/analysis_types.md` | Supported analysis types: Static, Dynamic, Heat Transfer, Coupled, etc. |

| `base/snippets/` | Tested execution snippets (cantilever beam E2E). |

| `base/known_issues.md` | Vendor quirks and workarounds discovered during testing. |

## solver/2026/ — Abaqus 2026 specifics

- `solver/2026/notes.md` — Abaqus 2026 version notes and quirks.

---

## Hard constraints (apply to every session)

0. **Respect the Abaqus embedded-Python boundary.** Ordinary file-side

plotting/post-processing follows the sim-cli Python-helper environment

guidance. Abaqus/CAE and ODB scripts are different: execute them through

`sim run --solver abaqus script.py` so Abaqus launches its embedded Python

with the vendor modules available.

1. **Availability first.** Run `sim check abaqus` before creating files. If

it reports `not_installed`, do not keep trying random paths. Ask the user

to install Abaqus or set `SIM_ABAQUS_COMMAND` / `ABAQUS_COMMAND` /

`ABAQUS_BAT_PATH` to the exact launcher, for example

`C:\SIMULIA\Commands\abq2026.bat`.

2. **Never invent Category A defaults.** Geometry, materials, BCs,

analysis type, acceptance criteria — if missing, ask the user.

3. **Acceptance != exit code.** Validate against physics-based criteria

(displacement, stress, temperature ranges), not just `exit_code == 0`.

4. **Input deck keywords are case-insensitive** but use `*UPPERCASE` by

convention. Always include `*HEADING`.

5. **Working directory matters.** Abaqus creates output files (.dat, .odb,

.msg, .sta) next to the input file. Use `cwd` appropriately.

6. **Use the right mode.** If the model is already fully specified, prefer

`sim run --solver abaqus file.inp` or `sim run --solver abaqus script.py`.

If the agent is building/debugging the model incrementally, use

`sim connect --solver abaqus --mode cae` and iterate with `sim exec`. Use

`--backend bridge` when repeated small snippets need a live in-memory CAE

session.

7. **Save and inspect after every modeling step.** In CAE authoring mode,

each snippet should leave the `.cae` database in a coherent state and then

check `sim inspect cae.model_summary` or `sim inspect job.diagnostics`.

8. **Check docs or probe before guessing APIs.** If unsure about an Abaqus

keyword, CAE method, command option, or output variable, follow

`base/reference/doc_lookup.md` before editing the real model.

---

## Required protocol

After `sim check abaqus` confirms the solver is available: gather Category A

inputs from the user (geometry, material properties, loads, BCs, analysis

For batch work: write the `.inp` deck or `.py` script, lint with `sim lint`,

execute with `sim run --solver abaqus`, then choose the post-processing path

by artifact: `.dat` -> Python text parsing on the fetched file; ODB -> vendor

Python via `sim run --solver abaqus script.py` (sim-cli is the right and only

tool here). For ordinary file-side post-processing and plotting, follow the

sim-cli Python-helper environment guidance. Validate against physics-based

For modeling/debug/reporting work: start `sim connect --solver abaqus --mode