A flexible multi-body model of a surface miner for analyzing the interaction between rock-cutting forces and chassis vibrations

The discontinuous nature of rock cutting can easily cause unwanted vibrations in the structure of a surface miner. If these vibrations are not properly addressed, the related stress cycles can gradually damage the chassis resulting in fatigue failures. These events can seriously undermine the safety of operators and digging operations may be stopped for days, with an obvious economic impact. This work presents an analysis of the dynamics of a surface miner, focusing on the interaction between cutting machine dynamics and cutting forces, which is a new approach for this type of machine. For this purpose, the authors developed a numerical model of the cutting process made up of (1) a multi-body model of the cutting machine, which takes into account the chassis’s flexibility; (2) a model of the rotating cutting head; and (3) a model of the interaction between the cutting head and rock, based on Shao’s model. The model was compared with experimental results and then used to investigate the effects of cutting speed and cutting depth on the machine dynamics