mdof.modal module#

This module implements functions that extract modal information from a state space realization or transfer function.

mdof.modal.system_modes(realization, dt, **options)#

Modal identification from a state space system realization.

Parameters:

  • realization (tuple) – realization in the form of state space coefficients (A,B,C,D)

  • dt (float) – timestep.

  • decimation (int, optional) – decimation factor. default: 1

  • Observability (array, optional) – Observability matrix; can be reused from mdof.realize.srim(). default: None

Returns:

system modes, including natural frequencies, damping ratios, mode shapes, condition numbers, and modal validation metrics EMAC and MPC.

Return type:

dictionary

mdof.modal.spectrum_modes(periods, amplitudes, **options)#

Modal identification from a transfer function.

Parameters:

  • periods (array) – transfer function periods

  • amplitudes (array) – transfer function amplitudes

Returns:

(fundamental_periods, fundamental_amplitudes)

Return type:

tuple