Open Cut » Maintenance & Equipment
Metal fatigue is an important consideration in the open cut coal mining industry due to the prevalence of heavy-duty machinery and harsh operating conditions intrinsic to mining operations. Cyclic loading and environmental stresses can accelerate metal fatigue, leading to premature equipment and infrastructure failures. This not only poses significant safety risks but may also result in costly repairs, operational downtime, and decreased productivity.
Typical fatigue management strategies often involve regular maintenance and inspections of equipment based on the number of hours in service. Time based scheduling of these interventions is not an optimal strategy as the number of hours in service is not necessarily representative of the damage incurred. Prioritising maintenance and inspections based on a measurement of structural fatigue presents a more efficient use of mine maintenance resources. This project aimed to develop and assess an unpowered (passive) means of quantifying mechanical fatigue in steel components and structures without requiring the use of specialised data acquisition equipment and niche technical skills.
The project produced three different fatigue gauge designs for evaluation. Each gauge variant was designed on the basis of different approaches in assessing mechanical fatigue. These include:
- Based on the observation of crack initiation in samples with varying strain amplification factors;
- Based on the observation of crack initiation in samples with varying notch geometries; and
- Based on the observation of crack growth rates in a pre-cracked sample.
Unfortunately, given the limitations and caveats of passive fatigue sensor performance, this method of fatigue assessment was not considered a suitable alternative to conventional strain gauge measurement strategies.