Rotor.run_ucs(stiffness_range=None, bearing_frequency_range=None, num_modes=16, num=20, synchronous=False, **kwargs)

Run Undamped Critical Speeds analyzes.

This method will run the undamped critical speed analyzes for a given range of stiffness values. If the range is not provided, the bearing stiffness at rated speed will be used to create a range.

stiffness_rangetuple, optional

Tuple with (start, end) for stiffness range in a log scale. In linear space, the sequence starts at base ** start (base to the power of start) and ends with base ** stop (see endpoint below). Here base is 10.0.

bearing_frequency_rangetuple, optional

The bearing frequency range used to calculate the intersection points. In some cases bearing coefficients will have to be extrapolated. The default is None. In this case the bearing frequency attribute is used.


Number of steps in the range. Default is 20.

num_modesint, optional

Number of modes to be calculated. This uses scipy.sparse.eigs method. Default is 16. In this case 4 modes are plotted, since for each pair of eigenvalues calculated we have one wn, and we show only the forward mode in the plots.


If True a synchronous analysis is carried out and the frequency of the first forward model will be equal to the speed. Default is False.


For more information on attributes and methods available see: ross.UCSResults