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The bolter miner is a critical piece of equipment in the rapid set of tunneling equipment, and the load generated during coal cutting may lead to excessive vibration of the equipment and reduce its reliability. In order to reduce the vibration response of the bolter miner, this paper proposes the installation of a dynamic vibration absorber (DVA) inside the cutting arm of the bolter miner. A five-degree-of-freedom dynamics model was developed, and the cutting part was regarded as two rigid bodies flexibly connected by a rotating spring. The model's accuracy was verified based on the field test results, and the error was within 7%. It was found that the cutting caused the first-order modal vibration, and the DVA was placed in the cavity of the cutting arm to control the modal vibration of this order. To minimize the vibration, a coupled dynamics model between the DVA and bolter miner was developed, and the DVA parameters were optimized. The results showed that the acceleration RMS and peak values of the cutting part were reduced by 12% and 30.1%, respectively; the acceleration RMS and peak values of the main frame were reduced by 6.5% and 17%, respectively, and the fatigue life of the cutting arm was increased by 34.2%. [ABSTRACT FROM AUTHOR]

In the operation of bolter miners, the cutting arm is an essential and weak part and its fatigue life directly affects its performance. This study aimed to investigate the influence of the cutting head load on the fatigue life of a cutting arm using the DEM-MFBD (Discrete Element Method-Multi Flexible Body Dynamics) bi-directional coupling technique. The EJM340 bolter miner was chosen as the research object, and a three-dimensional solid model of the bolter miner was built using the RecurDyn software. The cutting arm was flexibly modelled, and the tunnel model was built using the EDEM software. The motion parameters of the bolter miner and cutting head load were transferred through the bi-directional coupling interface to obtain the loads and stress parameters during the entire tunnel cutting process. Based on the stress-time variation, the fatigue life of the cutting arm was calculated, the overall damage and crack initiation locations were obtained, and the minimum number of cutting arm cycles was determined. The accuracy of the virtual model is verified through field experiments. The analysis results indicated that the crack emergence location and fatigue life obtained from the simulation were in agreement with the experimental results. [ABSTRACT FROM AUTHOR]