...Jian-Chao Zhang; Li-Wei Cai; Zhan Chen; Xing-Ke Qi In order to study the dynamic characteristics of a high-speed train gear transmission system with cracks, time-varying meshing stiffness of gear teeth with different cracks was obtained using energy method. A torsional vibration model of the gear...

... to low drilling efficiency or even causing the downhole tools failure. Therefore, establishing the stick–slip theoretical model, which is more consistent with the actual field conditions, is the key point for new drilling technology. Based on this, a new torsional vibration tool is proposed in this paper...