In the pioneer CAE stage, life assessment is the essential part to make the product meet the life requirement. Commonly, the lives of flexible structures are determined by vibration fatigue which accrues at or close to their natural frequencies. However, existing PSD vibration fatigue damage estimation methods have two prerequisites for use: the behavior of the mechanical system must be linear and the probability density function of the response stresses must follow a Gaussian distribution. Under operating conditions, non-Gaussian signals are often recorded as excitation (usually observed through kurtosis), which will result in non-Gaussian response stresses. A new correction is needed to make the PSD approach available for the non-Gaussian vibration to deal with the inevitable extreme value of high kurtosis. This work aims to solve the vibration fatigue estimation under the non-Gaussian vibration; the key is the probability density function of response stress. This work researches the importance of non-Gaussianity numerically and experimentally. The beam specimens with two notches were used in this research. All excitation stays in the frequency range that only affects the second natural frequency, although their kurtosis is different. The results show that the probability density function of response stress under different kurtoses can be obtained by kurtosis correction based on the PSD approach of the frequency domain.

Currently, braking control systems used in regional railways are open-loop systems, such as metro and tramways. Given that the performance of braking can be influenced by issues such as wheel sliding or the properties of the friction components present in brake systems, our study puts forward a novel closed-loop mechanism to autonomously stabilize braking performance. It is able to keep train deceleration close to the target values required by the braking control unit (BCU), especially in terms of the electrical–pneumatic braking transform process. This method fully considers the friction efficiency characteristics of brake pads and encompasses running tests using rolling stock. The test results show that the technique is able to stabilize the actual deceleration at a closer rate to the target deceleration than before and avoid wheel sliding protection (WSP) action, especially during low-speed periods.

Fatigue damage is the most dangerous failure behavior for gearbox suspenders in urban railway vehicles, and passenger capacity is crucial to the dynamic load characteristics of the traction transmission system. Therefore, in this paper, a dynamic model of the motor car is established, and a numerical simulation is carried out under different speeds and curve radii to investigate the effect of passenger capacity on fatigue life. The research results show that passenger capacity is an essential factor affecting the fatigue life of suspenders. As the vehicle runs at an average speed, the fatigue life of the suspender is 1.07 × 10⁶ km when the passenger capacity is 120 people; when there are 240 people, the fatigue life reduction is 60%, while it is 86% at 339 people and 92% at 389 people. The per capita fatigue damage under a straight line is 7.27 × 10⁻¹⁰ at 20 km/h but 1.23 × 10⁻⁸ at 60 km/h. The per capita fatigue damage under a curved line is 7.18 × 10⁻⁹ in the 600 m curve but 9.00 × 10⁻⁹ in the 400 m curve. It can be concluded that the effect of speed is more significant than the curve radius. This research achievement can provide theoretical support for vehicle design and maintenance decisions.

In order to improve the work efficiency and single function of the hedge trimming machine, this subject innovatively designs a vehicle-mounted double-arm hedge machine. It can trim the top and one side of the green belt at the same time. Real-time adjustment of the trimming angle and width can also trim the highway slope. Using SOLIDWORKS to establish the whole machine model and ADAMS to carry out simulation analysis on the model. The height of the cutting tool off the ground, the horizontal displacement and the load of each hydraulic cylinder in the process of movement are calculated. The rationality of the whole machine motion is verified, and the prototype is made based on the model and simulation results. The on-site operation proves that the designed vehicle-mounted double-arm hedge trimmer is feasible and innovative.