Fatigue life prediction of heavy mining equipment. Part 1: Fatigue load assessment and crack growth rate tests

Frequent fatigue failure of heavy mining equipment has created the need for fatigue life prediction of its cracked components. As the first step, field monitoring of a cable shovel boom that had a history of chronic fatigue cracking was conducted. A set of load spectra for the boom was constructed from the collected field data. A finite element model of the boom was prepared and calibrated against the test data to predict the stress and strain histories. Eight crack growth rate coupon tests were carried out to obtain the fatigue properties of the material used. Constant amplitude equivalent stress ranges were calculated based on Palmgren–Miner’s cumulative damage rule and crack growth rate tests results.