1. Reference problem

1.1. Geometry

A rotor model supported by 2 bearings (nodes \(\mathrm{B1}\) and \(\mathrm{B2}\) in the figure below), whose stiffness and damping matrices are non-symmetric. It is composed of 3 disks, and 3 shaft sections.

Figure 1.1-a -a: Rotor model with 2 discs and 2 asymmetric bearings

1.2. Material properties

The geometric and material characteristics are listed in the following table.

Material		\(E={2.10}^{11}N/{m}^{2}\)	\(\rho =7800\mathrm{kg}/{m}^{3}\)	\(\nu =0.3\)
Disc	\(\mathrm{D1}\)	\(M=3.5\mathrm{kg}\)	\({I}_{D}=3.5{10}^{-3}\mathrm{kg}{m}^{2}\)	\({I}_{P}={7.10}^{-3}\mathrm{kg}{m}^{2}\)
	\(\mathrm{D2}\)	\(M=3.0\mathrm{kg}\)	\({I}_{D}=3.0{10}^{-3}\mathrm{kg}{m}^{2}\)	\({I}_{P}={6.10}^{-3}\mathrm{kg}{m}^{2}\)

1.3. Boundary conditions

To block rigid body movements in direction \(Z\), we block the degree of freedom \(\mathit{DZ}\) at the level node \(\mathrm{B1}\).