Digital Model - Engineering Asset Lifecycle Management

Sustainable digital models for engineering assets built with sustainable engineering processes and solutions. Single source of truth for offshore, subsea, and marine engineering analysis.

Dedicated to Mark Cerkovnik - Chief Engineer, mentor, and inspiration.

🔍 Capabilities Snapshot

Lifecycle coverage: fatigue, stress, hydrodynamics, riser & mooring, metocean, vessel systems.
Digital thread: ASCII-first configs drive FE models, CAD/animations, reports, and QA workflows.
Data procurement: structured spec library for supplier intelligence across offshore domains.
Automation ready: modular APIs, CLI tooling, and integration hooks for pipelines & dashboards.
Validation tooling: cross-check analytical vs. numerical results with repeatable benchmarking.

🎯 Vision

Utilize a single source of ASCII inputs (promoting single source of truth) to generate equivalent analytical models encompassing the complete lifecycle operations of engineering assets:

Analytical Calculations - Fatigue, stress, hydrodynamics, structural capacity
Computational Analysis - FEA models, time-domain simulations, frequency analysis
3D CAD Models - Automated geometry generation
3D Animations - Visual representations of designs
Drawing Automation - Engineering documentation

📊 Repository Overview

Category	Count	Description
Python Modules	704+	Core engineering libraries
Test Files	1,971+	Comprehensive test coverage
Examples	12+	Working demonstrations
Documentation	352+	Technical guides and references
Commits	305+	Active development history

🚀 Key Features

✅ Single Source of Truth

ASCII-based input files (.yml, .json, .csv)
Generate FE models, analytical calculations, 3D CAD, animations, and drawings from one source
Version-controlled engineering data

✅ Modular Architecture

Import engineering assets using configuration files
Reusable components across projects
Standardized naming conventions for cross-team collaboration

✅ Analytical QA

Automated verification of computational results
Cross-validation between analytical and numerical methods
Weight checks, load verification, structural capacity validation

✅ Industry-Proven Workflows

20+ years of hands-on engineering experience
Validated by 200+ SURF engineers
Production-ready for offshore and marine projects

🔬 Core Capabilities

Fatigue Analysis Module ⭐ NEW

Comprehensive S-N Curve Database & Analysis Tools

221 S-N curves from 17 international standards:
- DNV (81 curves), BS 7608 (79), ABS (24), BP (25), Norsok (15), Bureau Veritas (14), API (2), Titanium (4)
Joint types: Plated welded, Tubular, Tubular nodal
Environments: In Air, Seawater with CP, Free Corrosion
Advanced plotting: Log-log, linear-log, SCF application, fatigue limit handling
Data formats: CSV, JSON for easy integration

from digitalmodel.fatigue.sn_curve_plotter import SNCurvePlotter

# Initialize plotter
plotter = SNCurvePlotter()

# Plot S-N curves with stress concentration factor
plotter.plot_curves(
    lookup_indices=[64, 175, 183],
    scf=2.0,
    include_fatigue_limit=True,
    plot_type='log-log',
    save_path='sn_curves.png'
)

Quick Access:

Data: /data/fatigue/
Examples: /examples/fatigue/
Documentation: /data/fatigue/README.md

CALM Buoy Operational Analysis ⭐ NEW

Interactive Dashboards for Mooring System Design

Complete reference dataset from Hengyi PMB project (Brunei)
13 CSV files covering all operational aspects:
- Environmental conditions (1-yr and 100-yr return periods)
- Mooring line properties and configurations (95mm Studless R3 chain)
- Performance analysis (offsets, tensions, safety factors)
- Vessel design (300k DWT tanker)
- Buoy geometry and hawser systems
Interactive HTML reports with Plotly visualizations
Production-ready for OrcaFlex model generation

from digitalmodel.mooring.calm_buoy import CALMBuoyReportGenerator

# Generate interactive HTML dashboard
generator = CALMBuoyReportGenerator("data/mooring/results/calm_buoy/project_specific/south_east_asia_project_1")
report_path = generator.generate_report()

Quick Access:

Data: /data/mooring/results/calm_buoy/
Reports: /reports/mooring/calm_buoy/
Documentation: /docs/PHASE5_CALM_BUOY_OPERATIONAL_ANALYSIS.md
Source: /src/digitalmodel/mooring/calm_buoy/

Key Features:

6-leg CALM buoy with 60° spacing
Operational (intact & 1 line damaged) scenarios
Survival (100-year metocean) scenarios
All safety factors exceed ABS requirements (SF > 2.0)
Full traceability to design reports

Structural Analysis

Stress Analysis

Von Mises stress calculations
Nonlinear stress-strain analysis
Multi-axial stress states
Stress concentration factors

Plate Capacity

Buckling analysis (DNV, API standards)
Ultimate strength calculations
Multi-plate structural systems
Stiffened panel analysis

Time-Series Analysis

Signal Processing

Fast Fourier Transform (FFT)
Inverse FFT (iFFT)
Peak energy frequency identification
Signal integration and differentiation
Statistical analysis

Hydrodynamics

Wave load calculations (DNV-RP-H103)
Drag and inertia coefficients
Circular and rectangular section hydrodynamics
Current profile generation

Engineering Asset Modeling

Risers

Catenary Risers (SCR) - Simple Catenary Riser analysis
Lazy Wave Risers (SLWR) - Buoyancy-supported configurations
Stack-up calculations - Material properties, weights, tensions

Mooring Systems

SALM - Single Anchor Line Mooring
Buoy systems - Hydrodynamic analysis
Anchor design - Load capacity verification
CALM Buoy Analysis ⭐ NEW - Comprehensive operational datasets with interactive dashboards

Subsea Infrastructure

Pipelines - On-bottom stability, span analysis
Flexibles/Umbilicals - Configuration design
Rigid Jumpers - Structural analysis

Vessels

Light Service Vessels
Intervention Vessels
Ship design calculations

Software Integration

OrcaFlex

Automated model generation from YAML
Post-processing and results extraction
Time-series analysis integration

WAMIT

Hydrodynamic coefficient processing
RAO (Response Amplitude Operator) analysis

AQWA

Model setup automation
Results post-processing

BEMRosetta

Boundary element method integration

📦 Installation

Quick Start (pip)

# Install from GitHub
pip install git+https://github.com/vamseeachanta/digitalmodel.git

# Or clone for development
git clone https://github.com/vamseeachanta/digitalmodel.git
cd digitalmodel
pip install -e .

Using Conda Environment

# Create environment from YAML
conda env create -f dev_tools/environment.yml
conda activate digitalmodel

# Or install package in existing environment
pip install -e .

🎯 Quick Examples

1. Fatigue S-N Curve Analysis

from digitalmodel.fatigue.sn_curve_plotter import SNCurvePlotter

plotter = SNCurvePlotter()

# List available curves
dnv_curves = plotter.list_curves(
    curve_type_filter='DNV',
    environment_filter='Air'
)
print(dnv_curves)

# Compare multiple standards
plotter.create_comparison_plot(
    reference_index=64,  # API curve
    comparison_indices=[175, 183, 190],  # BS, BV, ABS
    scf=1.5,
    save_path='standard_comparison.png'
)

2. Catenary Riser Analysis

from digitalmodel.tests import test_catenary_riser

# Run analysis with YAML configuration
test_catenary_riser.main()

3. Stress Analysis

from digitalmodel.stress import StressAnalyzer

analyzer = StressAnalyzer()
vm_stress = analyzer.von_mises_stress(
    sigma_x=100,  # MPa
    sigma_y=80,
    sigma_z=60,
    tau_xy=20,
    tau_yz=15,
    tau_xz=10
)
print(f"Von Mises Stress: {vm_stress:.2f} MPa")

4. Plate Buckling Analysis

from digitalmodel.analysis.plate_capacity import PlateCapacity

plate = PlateCapacity(
    length=2.0,      # meters
    width=1.0,
    thickness=0.02,
    material='API 5L X65'
)

capacity = plate.calculate_buckling_capacity()
print(f"Buckling Capacity: {capacity:.2f} kN")

📚 Documentation

Getting Started

Module Documentation

API Reference

🗂️ Repository Structure

digitalmodel/
├── src/digitalmodel/
│   └── modules/                    # 45+ specialized analysis modules
│       ├── aqwa/                   # AQWA hydrodynamic analysis
│       ├── blender_automation/     # 3D model generation
│       ├── catenary/               # Catenary calculations
│       ├── data_procurement/       # Data scraping/validation
│       ├── fatigue_analysis/       # S-N curves, damage accumulation
│       ├── marine_engineering/     # Environmental loading, wave spectra
│       ├── mooring/                # Mooring system design
│       ├── orcaflex/               # OrcaFlex simulation interface
│       ├── pipe_capacity/          # Pipe stress calculations
│       ├── reporting/              # Interactive HTML reports
│       └── ...                     # 35+ more modules
├── tests/domains/                  # Test suites (mirrors src structure)
├── specs/modules/                  # Module specifications (39 specs)
├── docs/domains/                   # Module documentation
├── examples/domains/               # Working examples per module
├── config/                         # Configuration files
│   └── templates/                  # Project templates
├── data/                           # Engineering databases
│   └── fatigue/                    # S-N curve library (17 standards)
├── scripts/                        # Automation scripts
├── .claude/                        # AI orchestration (670+ files)
│   ├── agents/                     # Agent definitions
│   ├── skills/                     # Skill library
│   └── commands/                   # CLI commands
└── .claude-flow/                   # Runtime coordination

🔧 Development Tools

Repository Hygiene

# Check for root directory violations
python tools/cleanup-root.py --dry-run

# Automatic cleanup
python tools/cleanup-root.py

# Enable pre-commit hook
git config core.hooksPath .githooks

Testing

# Run all tests
pytest

# Run specific module tests
pytest tests/test_fatigue_analysis.py

# Run with coverage
pytest --cov=digitalmodel --cov-report=html

Code Quality

# Format code
black src/digitalmodel

# Lint
flake8 src/digitalmodel

# Type checking
mypy src/digitalmodel

🌟 Recent Additions

September 2025

✨ Fatigue S-N Curve Database - 221 curves from 17 international standards
✨ Advanced Plotting Module - Log-log, linear-log, SCF, fatigue limits
✨ CLI Tools - Command-line interface for curve analysis
✨ Comprehensive Examples - 8 example scripts demonstrating capabilities

Key Features

Direct GitHub data access for remote projects
Multiple integration methods (URL, submodule, clone, sparse checkout)
Production-ready plotting matching industry Excel tools
Full documentation and API reference

🤝 Contributing

Contributions welcome! This library benefits from:

20+ years offshore/subsea engineering experience
200+ SURF engineers' collective insights
Active production use in major projects

How to Contribute

Fork the repository
Create a feature branch (git checkout -b feature/amazing-feature)
Commit your changes (git commit -m 'Add amazing feature')
Push to the branch (git push origin feature/amazing-feature)
Open a Pull Request

📖 Citation

When using this library in academic or commercial work, please cite:

@software{digitalmodel2025,
  author = {Achanta, Vamsee},
  title = {Digital Model: Engineering Asset Lifecycle Management},
  year = {2025},
  publisher = {GitHub},
  url = {https://github.com/vamseeachanta/digitalmodel}
}

For the S-N Curve Database specifically:

@dataset{sn_curve_database2025,
  author = {Achanta, Vamsee},
  title = {Fatigue S-N Curve Database for Offshore Structures},
  year = {2025},
  publisher = {GitHub},
  url = {https://github.com/vamseeachanta/digitalmodel/tree/main/data/fatigue},
  note = {221 curves from 17 international standards}
}

📧 Contact & Support

GitHub Issues: Report bugs or request features
Email: vamsee.achanta@aceengineer.com
LinkedIn: Vamsee Achanta

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

🙏 Acknowledgments

Dedicated to Mark Cerkovnik - Chief Engineer whose insights shaped major portions of this work and repository.

Special thanks to:

200+ SURF engineers who contributed insights over 20 years
Open-source community for foundational tools
Industry standards organizations (DNV, API, ABS, BS, Norsok, Bureau Veritas)

🔗 Related Projects

OrcaFlex - Dynamic analysis software
WAMIT - Wave analysis program
AQWA - Hydrodynamic analysis
BEMRosetta - BEM analysis tool

📊 Project Status

✅ Active Development - Regular updates and improvements
✅ Production Ready - Used in active engineering projects
✅ Well Documented - 352+ documentation files
✅ Tested - 1,971+ test cases
✅ Industry Validated - 20+ years of engineering experience

Last Updated: September 30, 2025 Version: 2.0.0 Total Commits: 305+

Name	diffraction-analysis
Description	Master skill for hydrodynamic diffraction analysis - AQWA, OrcaWave, and BEMRosetta integration

diffraction-analysis

SKILL.md