Rope properties

DAVE-rigging had build-in relations for MBL, weight, diameter and stiffness of ropes.

This notebook produces graphs to illustrate these relations.

• HPME and IWRC have the same diameter / MBL relation

• Steel IWRC and Cable-Laid have a stiffness of just over 100 MBL

• HPME has a stiffness of 30 MBL

import numpy as np
import matplotlib.pyplot as plt
from DAVE_rigging.rigging_properties import estimate_wire_properties

The history saving thread hit an unexpected error (DatabaseError('database disk image is malformed')).History will not be written to the database.

Loading DAVEcore from: c:\python\venvs\build2\Lib\site-packages\DAVEcore.cp311-win_amd64.pyd
DAVEcore version = 2.4113 from c:\python\venvs\build2\Lib\site-packages\DAVEcore.cp311-win_amd64.pyd
Temporary files are stored in C:\Users\MS12H\AppData\Local\Temp\tmpt_z9xqma - will be deleted when DAVE exits

MBLs = np.linspace(1,1000)

data = dict()
data['IWRC'] = [estimate_wire_properties(type='Steel IWRC sling', MBL=mbl) for mbl in MBLs]
data['CableLaid'] = [estimate_wire_properties(type='Cable-laid sling', MBL=mbl) for mbl in MBLs]
data['HPME'] = [estimate_wire_properties(type='HPME sling', MBL=mbl) for mbl in MBLs]

plt.figure(dpi=150)
for key, rope_props in data.items():
    EAt  = [data.EA / 9.81 for data in rope_props]
    plt.plot(MBLs, EAt, label = key)

plt.xlabel = 'MBL [t]'
plt.ylabel = 'EA [t]'
plt.grid()
plt.xlim(left = 0)
plt.ylim(bottom=0)
plt.legend()
plt.title('Rope stiffness [EA] as function of MBL');

plt.figure(dpi=150)
for key, rope_props in data.items():
    kgm  = [data.kgm for data in rope_props]
    plt.plot(MBLs, kgm, label = key)

plt.xlabel = 'MBL [t]'
plt.ylabel = 'weight per meter [kg/m]'
plt.grid()
plt.xlim(left = 0)
plt.ylim(bottom=0)
plt.legend()
plt.title('Rope weight / MBL relation');

plt.figure(dpi=150)
for key, rope_props in data.items():
    dia  = [data.dia for data in rope_props]
    plt.plot(MBLs, dia, label = key, 
             linestyle = ':' if key == 'HPME' else '-',
             linewidth = 2 if key == 'HPME' else 1)

plt.xlabel = 'MBL [t]'
plt.ylabel = 'diameter [mm]'
plt.grid()
plt.xlim(left = 0)
plt.ylim(bottom=0)
plt.legend()
plt.title('Rope diameter / MBL relation');