Op³ User Manual

Welcome to the user manual for Op³ Studio v1.0.0-rc1, the integrated numerical and digital-twin framework for offshore wind turbine foundation assessment.

Contents:

• 01_installation
• First Project
  • Launch the application
  • Open the NREL 5 MW sample project
  • Run a headless eigenvalue analysis
  • Cross-compare foundation modes
  • Save your own project
  • Generate a report
• Foundation Modes
  • Mode A - Fixed base
  • Mode B - 6x6 stiffness matrix
  • Mode C - Distributed BNWF
  • Mode D - Dissipation-weighted
  • Choosing a mode
• Decision Layer
  • Three-step procedure
  • Sensor channels
  • Value of information
  • Sequential updating
• Web Application - the six tabs
  • Tab 1 - 3D Viewer
  • Tab 2 - Bayesian Scour
  • Tab 3 - Mode D (alpha, beta)
  • Tab 4 - PCE Surrogate
  • Tab 5 - DLC 1.1 Time-series
  • Tab 6 - Compliance and Actions
• Case Study - KEPCO engineer assesses scour at a new site
  • The scenario
  • Step 1 - Launch the application
  • Step 2 - Create a project
  • Step 3 - Baseline eigenvalue analysis
  • Step 4 - Bayesian scour inference
  • Step 5 - Remaining capacity check
  • Step 6 - VoI check
  • Step 7 - Generate report
  • Step 8 - Compliance audit
  • What this demonstrates
• Compliance Audits
  • Running audits from the web application
  • Running audits from the command line
  • Interpreting the results
• Report Generator
  • Generating a report
  • Requirements
  • Customisation
• Troubleshooting
  • The web application shows an error card
  • Port 8050 is already in use
  • OpenSeesPy import fails
  • PDF report generation fails
  • Release audit shows FAIL on openfast_runner
  • Sequential tracker shows flat posterior
• API Reference
  • Core API
  • Web application API
  • Project file API
  • Sequential Bayesian API
  • Decision agent API

What Op³ is

Op³ is an open-source framework that combines four capabilities in a single package:

1. 3D geotechnical limit-analysis (via OptumGX) for load-bearing capacity and cyclic degradation of suction caisson foundations.

2. 1D structural dynamics (via OpenSeesPy) for eigenvalue, pushover, and transient response of wind turbine tower + rotor assemblies.

3. Aero-hydro-servo-elastic simulation (via OpenFAST coupling) for DLC 1.1 and DLC 6.1 design load cases.

4. Digital-twin decision layer (via a neural forward model, Bayesian fusion, and VoI analysis) for prescriptive maintenance.

All four capabilities are exposed through a single local-first web application, op3_viz, which runs on the engineer’s laptop with no cloud dependency.

What Op³ is not

• A replacement for certified commercial design software (BLADED, SACS). Op³ is positioned as a research-grade reference implementation and engineering analysis tool, not a certification package.

• A cloud service. No data ever leaves the engineer’s workstation unless the user explicitly exports a report or commits to a git repository.

• A black-box ML system. Every numerical result can be traced to a specific OpenSeesPy or OptumGX invocation, and every neural prediction comes with the underlying training data and residuals.

Citation

If you use Op³ in a publication, please cite:

@software{op3_v1_0_0_rc1,
    author = "Kim, Kyeong Sun",
    title = "Op^3: Integrated Numerical and Digital-Twin Framework
              for Scour Assessment of Offshore Wind Turbine Tripod
              Suction-Bucket Foundations",
    version = "1.0.0-rc1",
    year = "2026",
    doi = "10.5281/zenodo.19476542",
    url = "https://github.com/ksk5429/numerical_model"
}