An anchor drilling for a coal mine support system can liberate an operator from heavy work, but will cause serious vibration, which willbe transmitted to the pedestal roof bolter along manipulator. Based on multi-level transfer path analysis (MTPA) and modal superposition method (MSM), vibration model subsystem composed of joints manipulator with six degrees freedom (DOF) was established. Moreo...

in this paper, a new analytical method is proposed to study the effect of crack and axial load on vibration behavior and stability of the cracked columns. using the local flexibility model, the crack has been simulated by a torsional spring with connecting two segments of column in crack location. by solving governing eigenvalue equation, the effect of crack parameters and axial load on the nat...

Recent far-infrared vibration–rotation–tunneling experiments have probed intricate details of the hydrogen bond tunneling dynamics in the water trimer through excitation of intermolecular vibrational transitions to states of sequentially increasing energy. The experimentally observed bifurcation splitting in the water trimer evolves from an equally spaced quartet in the vibrational ground state...

Screed is the main working component device in a paver, it plays a very important role in the quality of construction regardless its performance is good or not. This study analyzes the paver screed’s dynamic characteristics and calculates its natural frequency and natural mode of vibration based on finite element technology. Modification method proved to have optimized the screed structure. The...

Low-frequency Raman spectra of the porous structure formed on C-implanted silicon were examined using the 514.5 and 488 nm lines of Ar laser. The sharp low-frequency Raman peaks were observed with narrow linewidth and large intensity. According to usual vibration theory of the elastic body and related symmetry analysis, they are identified as the localized acoustic phonon torsional modes result...

This paper set out to establish the dynamics model of shaft torsional vibration for direct-drive wind turbine with phenomenon unstable system vibration. The stability equilibrium point dynamical is investigated, and Routh–Hurwitz criterion used obtain a range values bifurcation control parameters. For stable point, domain calculated by constructing Lyapunov function. sensitivity analysis parame...

The rotation — torsion — vibration interaction in the normal and 1 5N isotopic species of Acetyl Cyanide is studied in the rotational spectrum of ground, first excited state of methyl torsion and first excited state of CCN in plane bending vibration. With respect to a previous -work [1] a more detailed check of a model with five degrees of freedom, comprising three for the overall rotation and ...

This paper investigates a low degree-of-freedom wheel model, which describes the lateral vibration of towed wheels, called the shimmy. The model takes into account the lateral deformation of the tyre and also the torsional elasticity and the damping of the steering mechanism. The lateral deformation of the wheel is modeled by the stretched-string like tyre model, which considers the relaxation ...

This paper analyzes the electromechanical interaction in a flywheel system with a doubly fed induction machine, used for wind farm power smoothing or grid frequency response control. The grid-connected electrical machine is subject to power control, and this can cause it to produce negative damping to the shaft torsional vibration. Resonance must be prevented, and this paper proposes a solution...