stress_strain_life_parameters_from_data¶

class
reliability.PoF.
stress_strain_life_parameters_from_data
(strain, stress, E, cycles=None, print_results=True, show_plot=True)¶ This function will use stress and strain data to calculate the stressstrain parameters: K, n. If cycles is provided it will also calculate the strainlife parameters: sigma_f, epsilon_f, b, c.
It is not posible to calculate the strainlife parameters without stress because stress is needed to find elastic strain.
If you already have the parameters K, n, sigma_f, epsilon_f, b, c, then you can use the function ‘stress_strain_diagram’ for the plot.
Parameters:  strain (array, list) – The strain values
 stress (array, list) – The stress values
 E (int, float) – The modulus of elasticity. Ensure this is in the same units as stress (typically MPa).
 cycles (array, list, optional) – The number of cycles to failure. Optional input. This is required if you want to obtain the parameters sigma_f, epsilon_f, b, c
 print_results (bool, optional) – If True the results will be printed to console. Default is True.
 show_plot (bool, optional) – If True the stress strain diagram will be produced. Default is True. Use plt.show() to show it.
Returns:  K (float) – The cyclic strength coefficient
 n (float) – The cyclic strain hardening exponent
 sigma_f (float) – The fatigue strength coefficient. This is only generated if cycles is provided.
 epsilon_f (float) – The fatigue strain coefficient. This is only generated if cycles is provided.
 b (float) – The elastic strain exponent. This is only generated if cycles is provided.
 c (float) – The plastic strain exponent. This is only generated if cycles is provided.