PFC5 Core Modeling

Use this skill for the version-pure foundation of a PFC 5.0 asphalt case. It replaces the reusable intent of the former general basics/contact workflow without restoring newer-major command files.

When To Use

• start or audit a PFC2D/PFC3D 5.0 case;
• create domains, walls, balls, clumps, groups, or ranges;
• plan current-contact versus future-contact model assignment;
• organize build, compaction, contact installation, equilibrium, and save stages;
• classify accepted, restart-only, diagnostic-only, failed, and obsolete states;
• detect unsupported-version syntax in a PFC5 source tree.

Route detailed gradation/void closure to pfc-asphalt-mixture, FISH to pfc5-fish, servo/calibration to pfc5-servo-calibration, and migration or recovery of an existing private case to pfc5-case-handoff.

Required Inputs

• PFC2D/PFC3D 5.0, units, sign convention, and runtime route;
• specimen/domain dimensions and boundary behavior;
• particle/clump size and shape abstraction;
• material/contact pair table;
• seed, equilibrium criterion, save/output contract.

Workflow

1. Freeze version, dimension, units, axes, seed, and object abstractions.
2. Create a clean model and domain before domain-sensitive objects.
3. Define future-contact defaults with PFC5 top-level cmat.
4. Create boundaries, particles/clumps, groups, and reusable ranges.
5. Form contacts, then audit counts/types before changing existing contacts.
6. Compact or equilibrate to an explicit criterion.
7. Install final contacts transactionally: save, apply, cycle, audit, solve, save.
8. Initialize measurements before loading. If energy histories are required, enable mechanical energy tracking before the measured interval.
9. Run scripts/audit_pfc5_case.py and an actual PFC5 syntax probe.

For an existing project, restore and audit the last claimed accepted state before a full rebuild. A restart-only state may seed a recovery branch only when its object and geometry invariants are known; re-run the original final gates without weakening them.

Read stage-gates.md for lifecycle checks and pfc5-command-boundary.md when auditing syntax.

Non-Negotiable Rules

• Do not infer PFC5 compatibility from an extension or old filename.
• Separate future defaults from existing-contact reassignment.
• Order non-default CMAT slots deliberately: PFC5 selects the first matching range, then falls back to the default slot for that contact type.
• Treat multiple solve limits as alternatives, not cumulative acceptance gates; record which limit terminated the solve.
• Do not delete all contacts as a generic model-switch recipe.
• cmat apply replaces the whole selected contact model and discards its prior stored state; save and audit before applying it.
• A fixed cycle count does not prove equilibrium.
• Source audit is static evidence only; runtime acceptance remains required.

Output Contract

Return the PFC5 stage map, object/group/range map, contact assignment table, equilibrium criteria, save map, audit report, and runtime_validated status.

Local Contents

• references/stage-gates.md — build-to-delivery gates.
• references/pfc5-command-boundary.md — syntax-family boundary.
• scripts/audit_pfc5_case.py — deterministic source-tree audit.
• agents/openai.yaml — interface metadata.