重型采矿设备的疲劳寿命预测第一部分:疲劳荷载评估和裂纹发展速度试验

Fatigue Life Prediction of Heavy Mining Equipment. Part 1: Fatigue Load Assessment and Crack Growth Rate Tests

重型采矿设备的疲劳寿命预测十分重要。首先,对早已存在有慢性疲劳裂纹的铲矿机起动臂进行现场监测,从监测数据中归纳了吊杆的载荷范围。针对试验数据,建立吊杆的有限元模型来预测其压应力和应变。进行了8个裂纹发展速度试验,获得使用材料的疲劳特性。基于Palmgren-Miner’s累积损坏原则和裂纹发展速度的试验结果,计算出恒振幅的换算应力范围。

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.