# stress_strength¶

class reliability.Other_functions.stress_strength

Given the probability distributions for stress and strength, this module will find the probability of failure due to stress-strength interference. Failure is defined as when stress>strength. The calculation is achieved using numerical integration.

Parameters: stress (object) – A probability distribution from the Distributions module strength (object) – A probability distribution from the Distributions module show_plot (bool, optional) – If True the distribution plot will be shown. Default = True. print_results (bool, optional) – If True, the results will be printed to console. Default = True. warn (bool, optional) – A warning will be issued if both stress and strength are Normal as you should use stress_strength_normal. You can supress this using warn=False A warning will be issued if the stress.mean > strength.mean as the user may have assigned the distributions to the wrong variables. You can supress this using warn=False. Default = True probability_of_failure (float) – The probability of failure due to stress-strength interference

Notes

Example usage:

from reliability.Distributions import Weibull_Distribution, Gamma_Distribution
stress = Weibull_Distribution(alpha=2,beta=3,gamma=1)
strength = Gamma_Distribution(alpha=2,beta=3,gamma=3)
stress_strength(stress=stress, strength=strength)