Miner's rule sums damage ratios of load cycles to estimate remaining life.
Combine S-N or strain-life curves, cycle counting (rainflow) and Miner's rule ΣnᵢNᵢ=1 to estimate life under variable loading. Corrections for mean stress, size, surface and reliability are applied. Validate with tests.
A bridge detail's life is assessed from traffic load spectra.
Miner's rule estimates fatigue life under variable loading, which is common in real machines and vehicles.
Miner's rule sums damage ratios of load cycles to estimate remaining life.
Miner's rule estimates fatigue life under variable loading, which is common in real machines and vehicles.
The total damage is the sum of the fraction of life used by each load level, and failure is predicted when the sum reaches one.
It ignores the order of loading and load interactions, so it can be non-conservative for some sequences.
Typical applications include estimating the remaining life of a crane hook after mixed load cycles, planning inspection intervals for a truck chassis with variable loads and combining damage from a day of different machine loads.
Study "Contact mechanics" first (topic 104 of 106 in Engineering Mechanics). It covers the groundwork this topic builds on.
Rainflow cycle counting. Linear damage accumulation. Safety factors on life.
A bridge detail's life is assessed from traffic load spectra.
The next topic is "Nonlinear finite element analysis", which builds directly on this one.
It is classed as Advanced in Engineering Mechanics (topic 105 of 106). It is an advanced topic. It assumes you are comfortable with the intermediate topics in Engineering Mechanics.
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