# Example 4 - Anisotropic Bearings.#

In this example, we use the rotor seen in Example 5.9.2 from .

Both bearings have a stiffness of 1 MN/m in the x direction and 0.8 MN/m in the y direction. Calculate the eigenvalues and mode shapes at 0 and 4,000 rev/min and plot the natural frequency map for rotational speeds up to 4,500 rev/min.

import ross as rs
import numpy as np
import plotly.graph_objects as go
import plotly.io as pio

pio.renderers.default = "notebook"

# Classic Instantiation of the rotor
shaft_elements = []
bearing_seal_elements = []
disk_elements = []
steel = rs.steel

for i in range(6):
shaft_elements.append(rs.ShaftElement(L=0.25, material=steel, n=i, idl=0, odl=0.05))

disk_elements.append(
rs.DiskElement.from_geometry(n=2, material=steel, width=0.07, i_d=0.05, o_d=0.28)
)

disk_elements.append(
rs.DiskElement.from_geometry(n=4, material=steel, width=0.07, i_d=0.05, o_d=0.35)
)
bearing_seal_elements.append(rs.BearingElement(n=0, kxx=1e6, kyy=0.8e6, cxx=0, cyy=0))
bearing_seal_elements.append(rs.BearingElement(n=6, kxx=1e6, kyy=0.8e6, cxx=0, cyy=0))

rotor592c = rs.Rotor(
shaft_elements=shaft_elements,
bearing_elements=bearing_seal_elements,
disk_elements=disk_elements,
)

rotor592c.plot_rotor()