FLife 1.1

Vibration Fatigue by Spectral Methods.

FLife - Vibration Fatigue by Spectral Methods

Obtaining vibration fatigue life in the spectral domain.

Installing this package

Use pip to install it by:

$ pip install FLife

Supported methods in the frequency-domain

• Dirlik,

• Tovo Benasciutti,

• Zhao Baker,

• Narrowband,

• Alpha 0.75,

• Wirsching Light,

• Rice,

• Gao Moan,

• Petrucci Zuccarello.

Rainflow (time-domain) is supported using the fatpack package.

Simple examples

Here is a simple example on how to use the code:

import FLife
import numpy as np


dt = 1e-4
x = np.random.normal(scale=100, size=10000)

C = 1.8e+22  # S-N curve intercept [MPa**k]
k = 7.3 # S-N curve inverse slope [/]

# Spectral data
sd = FLife.SpectralData(input=x, dt=dt)

# Rainflow reference fatigue life
# (do not be confused here, spectral data object also holds the time domain data)
rf = FLife.Rainflow(sd)

# Spectral methods
dirlik = FLife.Dirlik(sd)
tb = FLife.TovoBenasciutti(sd)
print(f'          Rainflow: {rf.get_life(C = C, k=k):4.0f} s')
print(f'            Dirlik: {dirlik.get_life(C = C, k=k):4.0f} s')
print(f'Tovo Benasciutti 2: {tb.get_life(C = C, k=k, method="method 2"):4.0f} s')

Reference: Janko Slavič, Matjaž Mršnik, Martin Česnik, Jaka Javh, Miha Boltežar. Vibration Fatigue by Spectral Methods, From Structural Dynamics to Fatigue Damage – Theory and Experiments, ISBN: 9780128221907, Elsevier, 1st September 2020, see Elsevier page.