pycatenary

Features

This python package solves catenary equations for cables at static equilibrium.

• Elasticity taken into account
• Contact with floor/seabed taken into account
• Handles partly or fully lifted lines
• Multisegmented cables possible

Installation

Through pip:

pip install pycatenary

or by running the following command in the root folder of the pycatenary project

python setup.py install --user

Getting Started

To create a cable:

from pycatenary import cable

# define properties of cable
length = 6.98  # length of line
w = 1.036  # submerged weight
EA = 560e3  # axial stiffness
floor = True  # if True, contact is possible at the level of the anchor
anchor = [0., 0., 0.]
fairlead = [5.2, 1., 2.65]

# create cable instance
l1 = cable.MooringLine(L=length,
                       w=w,
                       EA=EA,
                       anchor=anchor,
                       fairlead=fairlead,
                       floor=floor)

# compute calculations
l1.computeSolution()

Position of fairlead and anchor can be changed as follows:

# change fairlead position
l1.setFairleadCoords([5.4, 1., 2.65])

# recompute solution
l1.computeSolution()

Other useful functions:

# get tension along line (between 0. and total line length)
s = 5.
T = l1.getTension(s)

# get xyz coordinates along line
xyz = l1.s2xyz(s)

For extra functionality, please refer to the documentation: https://tridelat.github.io/pycatenary

Plotting

With matplotlib installed, the cable can be plotted in 2D:

# plot cable cable.MooringLine instance l1
l1.plot2D()

Or in 3D:

# plot cable cable.MooringLine instance l1
l1.plot3D()