A parameter study is presented to determine effects of planet gear design parameters on the global modal behaviour planetary geared rotor systems. The sensitivity analysis conducted using a three-dimensional dynamic model system for number gears, mistuning, mass mesh stiffness and speed. These have varying impacts both natural frequencies mode shapes, therefore vibration modes determined by com...

Odontoid process fracture accounts for 5% to 15% of all cervical spine injuries, and the rate is higher among elderly people. The anterior cannulated screw fixation has been widely used in odontoid process fracture, but the fixation strength may still be limited under some circumstances. This study aims to investigate the biomechanical fixation strength of expansive double-threaded bi-direction...

While the rule of mixture is applicable for addressing the overall Poisson's ratio of a concentrically aligned bi-layered rod under longitudinal loading, the same cannot be said for this rod under torsional loading due to the higher extent of deformation in the rod material further away from the torsional axis. In addition, the use of adhesives for attaching the solid inner rod to the hollow ou...

Nonlinear dynamic model of the coupled lateral-torsional vibrations of a gear transmission system is developed, in which time-varying gear meshing stiffness, errors, and gaps are considered. The fundamental rules of the system’s multi-harmonic dynamic response have been obtained based on the time domain diagram, frequency domain diagram, phase plot, and Poincaré map. Therefore, estimation of th...