FSSLibrary

A comprehensive Python library designed for the Floating and Submerged Structures course at TU Delft. This library provides essential tools for marine and ocean engineering calculations, including linear wave theory, structural beam analysis, mooring systems, and wave spectrum processing.

Features

🌊 Wave Analysis

• Linear Wave Theory: Dispersion relations, wave length calculations, and 2D linear wave analysis
• Wave Spectrum Processing: Comprehensive spectral analysis tools for irregular waves
• FFT-based Signal Processing: Single-sided spectrum computation and frequency domain analysis

🏗️ Structural Analysis

• Beam Matrices: Mass, stiffness, and damping matrices for both 2D and 3D beam elements
• Finite Element Support: Essential matrices for structural dynamics of marine structures

⚓ Mooring Systems

• Catenary Analysis: Mooring line calculations with extensible cable dynamics
• Static Analysis: Position and tension calculations for mooring systems

🧮 Utilities

• Physical Constants: Standard marine engineering constants (gravity, water density, etc.)
• Optimization Tools: Integrated scipy-based solvers for engineering problems

Installation

Prerequisites

• Python 3.7 or higher
• Required dependencies: numpy, scipy, ipykernel

Install from source

git clone https://github.com/CMOE-TUDelft/FSSLibrary.git
cd FSSLibrary
python -m pip install -e .

Install dependencies

python -m pip install -r requirements.txt

Quick Start

import FSSLibrary as fss
import numpy as np

# Linear wave analysis
wave = fss.LinearWave.LinearWave2D(d=50.0, T=8.0, H=2.0)
print(f"Wave length: {wave.L:.2f} m")

# Wave spectrum processing
fs = 10.0  # Sampling frequency
signal = np.random.randn(1024)  # Example signal
f, amp, psd = fss.FFTBasic.get_single_sided_spectrum(signal, fs)

# Access physical constants
print(f"Gravity: {fss.Constants.g} m/s²")
print(f"Water density: {fss.Constants.rhoW} kg/m³")

Module Overview

Module	Description
LinearWave	Linear wave theory, dispersion relations, 2D wave calculations
WaveSpectrum	Wave spectral analysis and irregular wave generation
BeamMatrices	2D/3D beam finite element matrices for structural analysis
MoorLib	Mooring line catenary analysis and calculations
FFTBasic	FFT-based signal processing and spectrum analysis
Constants	Physical constants for marine engineering

Documentation

Generate Documentation with pdoc

To generate and serve the documentation locally using pdoc:

# Install pdoc if not already installed
python -m pip install pdoc

# Generate static HTML documentation
pdoc --output-dir docs/ src/FSSLibrary

# Or Generate documentation and serve on localhost
pdoc --http localhost:8080 src/FSSLibrary

The documentation will be available at http://localhost:8080 when using the second command.

Pre-built Documentation

Pre-built HTML documentation is available in the docs/ directory. Open docs/index.html in your browser to view the complete API documentation.

Examples

Wave Length Calculation

from FSSLibrary.LinearWave import getWaveLen
from FSSLibrary.Constants import g

# Calculate wave length for given conditions
depth = 50.0  # m
period = 8.0  # s
wave_length = getWaveLen(g, depth, period)
print(f"Wave length: {wave_length:.2f} m")

Beam Matrix Generation

from FSSLibrary.BeamMatrices import Beam2DMatrices

# Define beam properties
mass_per_length = 100.0  # kg/m
axial_stiffness = 1e9    # N
bending_stiffness = 1e6  # N⋅m²
node_coords = ([0, 0], [10, 0])  # Start and end coordinates

# Generate matrices
M, K, Q = Beam2DMatrices(mass_per_length, axial_stiffness, 
                         bending_stiffness, node_coords)

Mooring Analysis

from FSSLibrary.MoorLib import catenary_xz

# Mooring line parameters
weight_per_meter = 50.0   # N/m
elastic_modulus = 1e8     # Pa
vertical_tension = 1000.0 # N
horizontal_tension = 800.0 # N
suspended_length = 100.0   # m

# Calculate catenary position
x, z = catenary_xz(weight_per_meter, elastic_modulus, 
                   vertical_tension, horizontal_tension, suspended_length)

Course Context

This library is specifically designed for the Floating and Submerged Structures course and provides:

• Educational implementations of fundamental marine engineering concepts
• Ready-to-use functions for course assignments and projects
• Clear, documented code suitable for learning and teaching
• Integration with Jupyter notebooks for interactive analysis

Development

Project Structure

FSSLibrary/
├── src/FSSLibrary/     # Main package source
├── docs/               # Pre-built documentation
├── requirements.txt    # Dependencies
├── pyproject.toml     # Package configuration
└── README.md          # This file

Testing

# Run basic import test
python -c "import FSSLibrary; print('Import successful')"

Authors

• Shagun Agarwal - shagun.1994@gmail.com
• Oriol Colomés - j.o.colomesgene@tudelft.nl

Delft University of Technology

License

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

Version

Current version: v0.2.0

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For course-related questions and support, please contact the course instructors.