PFC5 Coupling Skill: Validate Fluid-Solid Contracts

Where this fits

You're building an agent that automates PFC 5.0 asphalt studies involving fluid pore pressure, seepage, or PFC-FLAC coupling. You quickly realize that every run burns licensed solver hours, and most failures happen because the coupling contract (units, physics assumptions, exchange intervals) is wrong. The pfc5-coupling skill steps in to plan and validate those contracts before your agent touches the licensed solver, keeping version-specific commands and license assets external.

Why agents benefit

• Freezes coupling contracts in JSON – The agent writes a precise contract using the reference template, turning ambiguous physics into machine-checkable fields.
• Runs local validation – scripts/validate_coupling_contract.py checks paths, units, fields, and intervals without spending any licensed CPU time.
• Forces incremental testing – The workflow explicitly rejects two-way iteration until one-way exchange passes sign, scale, and conservation checks.
• Handles version and license boundaries – By keeping PFC5 commands and license assets external, the agent avoids hardcoding version-specific syntax that breaks across projects.
• Promotes restartable exports – Exchanged fields, residuals, timestamps, and restart state are logged, giving your agent a traceable audit trail for debugging.

Practical scenarios

1. Asphalt pavement pore-pressure study

The agent needs to model pore pressure buildup under repeated loading. It first checks whether a simpler prescribed pressure boundary suffices. If full coupling is required, it writes a contract with fluid density, viscosity, and exchange interval, then runs the validation script locally. Only after passing does it dispatch a minimal one-way PFC5 case to confirm the sign and scale of pressure response.

2. Seepage into a discrete-fracture network

You're coupling PFC2D with a continuum seepage solver. The agent must align coordinate systems and map boundary nodes between meshes. The skill's contract template forces explicit coordinate mapping and unit declarations, catching mismatched length or time units early. The validation script flags missing fields before any license is consumed.

3. Buoyancy-driven particle settling in PFC-FLAC

Your agent runs a two-way coupled simulation where particles settle and change porosity in the FLAC continuum. The skill directs the agent to start with one-way coupling (FLAC pushes forces to PFC) and then validate conservation of mass and momentum. Only after those checks pass does it allow two-way iteration, preventing common oscillatory instabilities.

Add it to your agent workflow

Install the skill with:

npx skills add Echo-aloha/asphalt-codex-skills-5 --skill pfc5-coupling

Then instruct your agent to read references/coupling-contract.md and run the validator before any licensed simulation. For example, your system prompt might say:

For any PFC coupling request, contract_json = generate_contract(inputs); run "python scripts/validate_coupling_contract.py --contract contract.json"; route to solver only if exit code is 0.

Compare before adopting

Before adding this skill to your registry, compare its contract schema against your existing PFC workflow. Check whether the validation script matches your internal unit conventions, whether the repo is maintained (last commit, open issues), and whether it supports your specific PFC-FLAC version. Also consider if your existing agent already has native coupling checks—this skill shines when you need a structured, reproducible contract standard.

Why it is worth tracking

With 31 stars and a focused scope, this skill is still young but addresses a real pain point: expensive PFC licensing wasted on contract errors. It provides a clear, testable interface that aligns with agent workflow best practices—validate cheaply first, then spend compute. Keep an eye on its update frequency and community feedback; once it gains more real-world usage, it could become the de facto contract format for PFC coupling studies. For another curated skill, see the full listing at OpenAgentSkill. Track it now, adopt when your coupling volume justifies the setup.