mechanical-sim

# mechanical-sim This file is the **Ansys Mechanical** index. Use DPF for solved `.rst` files on disk; use sim-cli/PyMechanical for live Mechanical sessions that mutate, solve, inspect, or update the GUI-backed project. This is **not** the Abaqus plugin. Do not run Abaqus `.inp` decks or Abaqus/CAE scripts here. Use `solver=abaqus` for Dassault SIMULIA Abaqus; use `solver=mechanical` only for Ansys Mechanical / PyMechanical sessions. The `/connect` response tells you which active layers apply: ```json "skills": { "root": "<sim-skills>/mechanical", "active_sdk_layer": "0.12", "active_solver_layer": "24.1" } ``` Always read `base/`, then your active `sdk/<version>/`, then your active `solver/<version>/`. Later layers override earlier ones on identically-named files. --- ## First principles 1. **Workbench orchestrates, Mechanical computes.** PyWorkbench drives Engineering Data / Geometry / Model. PyMechanical drives Setup / Solution / Results. Do not try to define boundary conditions via Workbench scripting — that belongs here. 2. **Observation is SDK+GUI coupled.** Every `uv run sim exec` is a `mechanical.run_python_script(code)` call that mutates Mechanical's in-memory model. Mechanical's window on the desktop redraws after each call. Therefore `uv run sim screenshot` (which grabs the desktop) always reflects the current SDK state. This coupling **only works with `batch=False`** — so the driver defaults to GUI mode. Confirm both `ui_mode == "gui"` and `batch == false` from `inspect session.summary` before relying on screenshots for GUI sync. 3. **Scripts run inside Mechanical's IronPython interpreter.** Globals `ExtAPI`, `DataModel`, `Model`, `Quantity`, `Tree` are already available — do NOT `import ansys.mechanical`. The last expression's string form is what `run_python_script` returns, so end snippets with a `json.dumps(...)` literal to get structured output. 4. **`ExtAPI.DataModel.Project` is the root.** From there: `.Model` → the scene; `.Model.Analyses[0]` → the first analysis; `.Model.Geometry` → bodies; `.Model.Mesh` → meshing controls; `.Model.Materials` → material assignments. --- ## base/ — always relevant | Path | What's there | |---|---| | `base/reference/pymechanical_api.md` | PyMechanical SDK surface: `launch_mechanical`, `run_python_script`, `download_project`, file transfer. **Read first.** | | `base/reference/scripting_tree.md` | Mechanical's IronPython scripting tree: `ExtAPI`, `DataModel`, `Model`, `Tree`, common traversal patterns. | | `base/reference/capability_discovery.md` | Generic method/feature discovery before adding analyses, BCs, results, or solve logic. Use this when the workflow differs from known snippets. | | `base/reference/bc_scoping.md` | Boundary condition scoping: creating `Selection` objects, `NamedSelection`, face IDs, `ISelectionInfo`. This is the #1 source of errors. | | `base/reference/solve_control.md` | Triggering solve (`analysis.Solution.Solve(True)`), monitoring state, reading solve messages. | | `base/reference/result_extraction.md` | Traversing `analysis.Solution` to pull deformation/stress values, exporting to CSV, using `.rst` files. | | `base/reference/observation_commands.md` | **How sim's observation commands couple with Mechanical.** Read this before using `uv run sim inspect` / `uv run sim screenshot` against a Mechanical session. | | `base/snippets/` | Numbered snippets (01_smoke through 06_extract_results). Each ends with a `json.dumps(...)` literal for structured output. | | `base/workflows/static_structural/` | End-to-end walk through cells 4-6, continuing where workbench-sim left off. | | `base/workflows/model_review_loop.md` | Required checkpoint loop: inspect health, project identity, model summary, then run one bounded snippet. | | `base/workflows/debug_failed_exec.md` | Failure triage loop for scoping, selections, mesh, solve, and result extraction failures. | | `base/workflows/workbench_handoff.md` | Workbench-to-Mechanical checklist for Static Structural workflows. | | `base/known_issues.md` | Quirks: Chinese locale gRPC, batch-mode stdin, IronPython Unicode, `Selection` vs `ISelectionInfo`. | ## sdk/<active_sdk_layer>/ - `sdk/0.12/` — PyMechanical 0.12 (works with Ansys 24.1–25.2). - `notes.md` — `launch_mechanical(version=241, batch=False)`, `wait_till_mechanical_is_ready`. ## solver/<active_solver_layer>/ - `solver/24.1/` — Ansys Mechanical 24.1. - `notes.md` — scripting namespace: which `ExtAPI` members exist in 24.1. --- ## Hard constraints 1. **Never launch with `batch=True`** unless the user has explicitly asked for headless mode. sim's observation commands need the GUI. 2. **Never `import ansys.mechanical.*`** inside a snippet that goes through `run_python_script`. The interpreter is Mechanical's embedded IronPython — the Python SDK is the wrong side of the wire. 3. **Always end snippets with `json.dumps(...)`** to get structured stdout. `run_python_script` returns only the last expression's repr. 4. **Workbench skill owns cells 1-3.** If the user asks for geometry import or material definition, hand back to workbench-sim. 5. **Never trust raw names or paths as public evidence.** Return counts, booleans, self-created ASCII tags, or sanitized strings from snippets. 6. **Discover live capabilities before coding a new workflow.** Use `mechanical.capabilities`, `mechanical.object.properties:*`, and official PyMechanical scripting docs to confirm available analysis, BC, result, and solve APIs. Do not infer physics support from `AnalysisType` strings alone. 7. **Observe long-running work out-of-band.** During solves, updates, imports, or hangs, use screenshots and file/message polling while the SDK call is blocked. Read `base/reference/observation_commands.md` before starting any expected long-running operation. ## Required protocol If the user's question is about an existing solved project (a `.rst` on disk), use DPF on the agent side; do not launch Mechanical at all. Before every Mechanical script: 1. Read `base/workflows/model_review_loop.md` and inspect `session.health`, `mechanical.project.identity`, and `mechanical.model.summary`. 2. For any workflow not already proven by a local snippet, read `base/reference/capability_discovery.md` and inspect `mechanical.capabilities` before adding setup objects. 3. Check `base/known_issues.md` for the operation you are about to do. 4. If this is a Workbench handoff, read `base/workflows/workbench_handoff.md` and confirm Mechanical sees the expected analysis and non-empty geometry. 5. For long-running solve/update/import steps, capture a screenshot before the call, then monitor with screenshots and available solver files/messages until it completes or clearly fails. 6. Run one bounded snippet, ending with `json.dumps(...)`. 7. Inspect `last.result`, `mechanical.model.summary`, and `mechanical.messages` after solve/result failures. In GUI mode, use a screenshot as visual confirmation after significant tree changes. 8. If execution fails, switch to `base/workflows/debug_failed_exec.md` before trying another full script.