To investigate the effect of the gear transmission system on the dynamic responses of the metro vehicle driving system, a vertical–longitudinal dynamics, model which considers the frame-hung traction motor and gearbox, is established and is validated to be reliable by comparing the simulation results and field test results in both time domain and time–frequency domain in this paper. Compared to wheelset, the gear mesh force has a greater effect on the force state of traction motor and gearbox.

The dynamic load-sharing characteristics of a face gear dual-power split transmission system (FGDPSTS) of an aircraft helicopter are studied. The effects of error, backlash, support clearance, spline clearance, torsional stiffness and support stiffness on dynamic load-sharing performance are analyzed. The load-sharing coefficient increases with the increase of the error, which provides a theoretical basis for the dynamic stability optimization design of the system.

We discuss a systematic electric vehicle design process. The steering geometry of the vehicle is analyzed, and the turning angle and radius are designed. The displacement of the vehicle under a load is calculated by rigidity analysis. The experimental modal analysis of the real frame and the finite element method are verified for the body-in-white manufacturing process. No-fuse switches and fuses are used to provide overcurrent protection. A solid-state relay is used for current protection.

This study carries out the complex eigenvalue analysis of influence factors of rail corrugation by using the three-dimensional finite-element model of a wheel–rail system based on the theory of friction self-excited vibration. The results show that improving the vertical and lateral stiffnesses of fasteners, controlling the wheel–rail friction coefficient below 0.4, and maintaining balanced superelevation can effectively reduce the occurrence possibility of rail corrugation.

The approach in this research includes data visualization and multilinear regression analysis. Multiple linear regression is a standard selection model in the world of data science. The approach turned out to be promising. However, the results reveal that the implemented technique holds a high degree of predictions, and the number of data sets is adequate. It is also observed that errors are in less concentration as the sum of squared errors is zero for every parameter.

The bending-torsional-axial coupling nonlinear dynamic model of double-sided meshing nutation drive system has been established. The modal analysis of double circular arc spiral bevel gears is carried out, and the ten order natural frequencies and their corresponding modes are obtained. The natural frequencies of nutation drive system and double circular arc spiral bevel gears are different, and there is no resonance.

A simple bicycle model considers only geometric and mass properties. Bicycle models considering compliance, tires, and rider posture are available. For the designer, it is important to know if the effect of geometric and mass properties on stability is correctly predicted by a simple bicycle model. Stability indices are calculated by means of bicycle models of increasing complexity. Results show that the simple model correctly predicts only the stability of the single modes.