# palmgren_miner_linear_damage¶

class reliability.PoF.palmgren_miner_linear_damage

Uses the Palmgren-Miner linear damage hypothesis to find the outputs:

Inputs: - rated life - an array or list of how long the component will last at a given stress level - time_at_stress - an array or list of how long the component is subjected to the stress that gives the specified rated_life - stress - what stress the component is subjected to. Not used in the calculation but is required for printing the output. Ensure that the time_at_stress and rated life are in the same units as the answer will also be in those units

Outputs: - Fraction of life consumed per load cycle - service life of the component - Fraction of damage caused at each stress level

Example usage: Ball bearings are fail after 50000 hrs, 6500 hrs, and 1000 hrs, after being subjected to a stress of 1kN, 2kN, and 4kN respectively. If each load cycle involves 40 mins at 1kN, 15 mins at 2kN, and 5 mins at 4kN, how long will the ball bearings last?

palmgren_miner_linear_damage(rated_life=[50000,6500,1000], time_at_stress=[40/60, 15/60, 5/60], stress=[1, 2, 4])