how to use couplinElement

[Pierre-zhu]

how to assembly coupling into rotor? or how to use couplingelement? could you give me one axample?

[jguarato]

Here is an example to clarify some details, however, it does not represent a real model:

import ross as rs
from ross.materials import steel

# Define the shafts with their respective dimensions and properties

# Shaft 1 - Left
L1 = [300, 92, 200, 200, 92, 300]  # Segment lengths (in mm)
r1 = [61.5, 75, 75, 75, 75, 61.5]  # Segment radii (in mm)
shaft1 = [
    rs.ShaftElement(
        L=L1[i] * 1e-3,  # Convert length to meters
        idl=0.0,  # Inner diameter in meters
        odl=r1[i] * 2e-3,  # Outer diameter in meters
        material=steel,  # Material used for the shaft
        shear_effects=True,
        rotary_inertia=True,
        gyroscopic=True,
    )
    for i in range(len(L1))
]

# Shaft 2 - Right
L2 = [80, 200, 200, 640]  # Segment lengths (in mm)
r2 = [160.5, 160.5, 130.5, 130.5]  # Segment radii (in mm)
shaft2 = [
    rs.ShaftElement(
        L=L2[i] * 1e-3,  # Convert length to meters
        idl=0.0,  # Inner diameter in meters
        odl=r2[i] * 2e-3,  # Outer diameter in meters
        material=steel,  # Material used for the shaft
        shear_effects=True,
        rotary_inertia=True,
        gyroscopic=True,
    )
    for i in range(len(L2))
]

# Define the coupling element that connects the two shafts

# Mass at each station (e.g., hub mass of the coupling)
mass_station = 151 / 2  # Assuming equal distribution of mass (in kg)

# Polar moments of inertia at the left and right stations of the coupling
Ip_station = 1.74  # Polar moment of inertia, assuming equal distribution (in kg·m²)

# For stiffness, in this example I considered just the torsional stiffness,
# but you can pass as arguments kt_x, kt_y, kt_z (axial), kr_x, kr_y, kr_z (torsional)
# The K matrix will be assembled like this:
# k1 = kt_x
# k2 = kt_y
# k3 = kt_z
# k4 = kr_x
# k5 = kr_y
# k6 = kr_z
# K = 
#     [  k1,    0,    0,    0,    0,    0, -k1,    0,   0,    0,   0,    0],
#     [   0,   k2,    0,    0,    0,    0,   0,  -k2,   0,    0,   0,    0],
#     [   0,    0,   k3,    0,    0,    0,   0,    0, -k3,    0,   0,    0],
#     [   0,    0,    0,   k4,    0,    0,   0,    0,   0,  -k4,   0,    0],
#     [   0,    0,    0,    0,   k5,    0,   0,    0,   0,    0, -k5,    0],
#     [   0,    0,    0,    0,    0,   k6,   0,    0,   0,    0,   0,  -k6],
#     [ -k1,    0,    0,    0,    0,    0,  k1,    0,   0,    0,   0,    0],
#     [   0,  -k2,    0,    0,    0,    0,   0,   k2,   0,    0,   0,    0],
#     [   0,    0,  -k3,    0,    0,    0,   0,    0,  k3,    0,   0,    0],
#     [   0,    0,    0,  -k4,    0,    0,   0,    0,   0,   k4,   0,    0],
#     [   0,    0,    0,    0,  -k5,    0,   0,    0,   0,    0,  k5,    0],
#     [   0,    0,    0,    0,    0,  -k6,   0,    0,   0,    0,   0,   k6],

torsional_stiffness = 3.04e6 # Torsional stiffness (in N·m/rad)

# Create the coupling element
coupling = rs.CouplingElement(
    m_l=mass_station,  # Mass on the left station
    m_r=mass_station,  # Mass on the right station
    Ip_l=Ip_station,   # Polar moment of inertia on the left station
    Ip_r=Ip_station,   # Polar moment of inertia on the right station
    kr_z=torsional_stiffness,  # Torsional stiffness
)

# Combine all elements into a single list for the rotor model
shaft_elements = [*shaft1, coupling, *shaft2]

# Build the rotor, you can also add bearings, disks, ...
rotor = rs.Rotor(shaft_elements)

# Plot the rotor to visualize the configuration
rotor.plot_rotor()

[Pierre-zhu]

Thanks for your help!
I sucess run finally , but with following error, if I save rotor as toml file:

File d:\ProgramData\Anaconda3\Lib\site-packages\spyder_kernels\py3compat.py:356 in compat_exec
exec(code, globals, locals) File ..\wvc_insideshafting\ross10v01_inside_coupling.py:107
rotor.save('rotor.toml')
File d:\ProgramData\Anaconda3\Lib\site-packages\ross\rotor_assembly.py:3132 in save
el.save(file)
File d:\ProgramData\Anaconda3\Lib\site-packages\ross\shaft_element.py:411 in save
"name": self.material.name,
AttributeError: 'CouplingElement' object has no attribute 'material'

[jguarato]

Thank you for reporting this problem. I will create an issue so this can be resolved.