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.

A novel structure of controlled multi-flow channel magnetorheological fluid semi-active mount is proposed, including four controlled channels and one rate-dip flow channel. For the proposed structural model, magnetic circuit analysis, rate-dip flow channel optimization design, and magnetorheological fluid mount damping analysis are performed, by developing a mathematical model for the semi-active mount of controlled multi-channel magnetorheological fluid.

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.

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.