free_modes_principal_axes

Transforms the rigid body modes defined at with the A frame as reference to the centre of mass position and aligned with the principal axes of inertia.

param phi:

Eigenvectors defined at the A frame.

type phi:

np.array

param mass_matrix:

System mass matrix

type mass_matrix:

np.array

param use_euler:

Use Euler rotation parametrisation rather than quaternions.

type use_euler:

bool

keyword return_transform:

Return tuple containing transformed modes and the transformation from the A frame to the P frame.

kwtype return_transform:

bool

returns:

Mass normalised modes with rigid modes defined at the centre of gravity and aligned with the

principal axes of inertia.

rtype:

np.array

References

Marc Artola, 2020