Sine and sine-sweep signal

Sine and sine-sweep signal#

Here are examples of how to determine the ERS and FDS of sine and sine-sweep signals:

Sine signal#

Import the required packages#

import numpy as np
import FatigueDS
import matplotlib.pyplot as plt

Instantiate Spectrum object#

Spectrum object contains data, required for the calculation of extreme response spectrum (ERS) and fatigue damage spectrum (FDS).

load_spectrum_1 = FatigueDS.Spectrum(freq_data=(0, 2000, 5), damp=0.1)

Set the sine load#

Set the sine load with the following parameters:

  • sine_freq - frequency of the sine signal

  • amp - amplitude of the sine signal

  • t_total - total time of the signal

  • exc_type - excitation type. Possible values are acc, vel and disp

load_spectrum_1.set_sine_load(sine_freq=500, amp=10, t_total=3600, exc_type='acc')

Calculate the ERS and FDS#

Calculate the ERS and FDS. For the FDS calculation, the additional mateiral fatigue parameters k, C and p must be provided.

load_spectrum_1.get_ers()
load_spectrum_1.get_fds(k=10, C=1e80, p=6.3 * 1e10)

Plot the results#

Plot the ERS and FDS results.

load_spectrum_1.plot_ers(label='sine')
load_spectrum_1.plot_fds(label='sine')

Or access the results directly:

load_spectrum_1.ers
load_spectrum_1.fds
load_spectrum_1.f0_range  # frequency vector

Sine-sweep signal#

Instantiate Spectrum object#

Spectrum object contains data, required for the calculation of extreme response spectrum (ERS) and fatigue damage spectrum (FDS).

load_spectrum_2 = FatigueDS.Spectrum(freq_data=(0, 2000, 5), damp=0.1)

Set the sine-sweep load#

Set the sine-sweep load with the following parameters:

  • const_amp - amplitude of the sine-sweep signal

  • const_f_range - frequency range of the sine-sweep signal

  • exc_type - excitation type. Possible values are acc, vel and disp

  • dt - time step

  • sweep_type - sweep type. Possible values are log and lin

  • sweep_rate - sweep rate

load_spectrum_2.set_sine_sweep_load(const_amp=[5, 10, 20], const_f_range=[20, 100, 500, 1000], exc_type='acc', dt=1, sweep_type='log', sweep_rate=1)

Calculate the ERS and FDS#

Calculate the ERS and FDS. For the FDS calculation, the additional mateirla fatigue parameters k, C and p must be provided.

load_spectrum_2.get_ers()
load_spectrum_2.get_fds(k=10, C=1e80, p=6.3 * 1e10)

Plot the results#

Plot the ERS and FDS results.

load_spectrum_2.plot_ers(label='sine sweep')
load_spectrum_2.plot_fds(label='sine sweep')

plt.show()

Or access the results directly:

load_spectrum_2.ers
load_spectrum_2.fds
load_spectrum_2.f0_range  # frequency vector
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