Search

Under the trend of promoting economy, environmental protection and high efficiency in the urban rail transit industry, this paper proposes a new type of straddle-type rapid transit system. Compared with most straddle-type monorail systems, it has the advantages of low construction cost and low operating cost, which makes it more suitable for urban rail transit system in small and medium-sized cities. In the process of vehicle development and design, in order to achieve the coordination and matching of tire systems and reduce the wear of tire systems, this work uses a multi-objective optimisation method to reduce the guiding torque of each tire system when the vehicle passes through the curve. Based on the vehicle dynamics model, the multi-body dynamics simulation model of the vehicle is established. The guiding torque of each tire system is taken as the optimisation objective, and the position and dynamic parameters of each tire system are taken as the optimisation parameter. Based on the NSGA-II algorithm, the ISIGHT and SIMPACK software are used for co-simulation. Finally, the guiding torque of each tire system is effectively reduced, and the coordination and matching of tire system is realised. [ABSTRACT FROM AUTHOR]

A common phenomenon of rail corrugation and its spatial distribution are observed in high-speed rail according to the overall and local field investigations, in which the rail corrugation with a wavelength of 100–300 mm and a depth of 0.01–0.05 mm normally occurs on both the rails in the sharp gradient sections of the high-speed rail. Then, a relevant simulation model of the wheelset–track system supported by the ballast-less track support structure and a wear model of track irregularity are built. Then, the typical phenomenon of rail corrugation on the high-speed rail is investigated from the aspect of the friction-induced vibration and the feedback vibration of wheelset–track, respectively. The obtained conclusions find that the friction-induced vibration caused by the saturated wheel–rail creep force is closely related to the appearance of rail corrugation in the sharp gradient of high-speed rail. Additionally, the feedback oscillation of corrugated wear with a shallow depth does not aggravate the rail corrugation, but may lead to a little difference in corrugation wavelengths in the same interval. [ABSTRACT FROM AUTHOR]

The dynamic parameters of Straddle-type monorail vehicles with single-axle bogies are optimised by utilising the multi-body dynamic method. The dynamic parameter optimisation is conducted aiming at the curve negotiation properties, comfort and tire eccentric wear of monorail vehicles. The optimisation model is established with software ADAMS and modeFRONTIER and the Sobol is adopted for sensitivity analysis to acquire the optimised parameters. Finally, the multiobjective collaborative optimisation algorithm is utilised for optimised analysis. According to the results, the proposed method can conduct multi-objective optimisation to the monorail vehicles in a successful way. The curve negotiation properties and comfort are improved, and the tire wear is reduced with dynamic parameters after optimisation. Especially, a conversion strategy of the consistent objective function is proposed aiming at multiobjective nonlinear convergence. [ABSTRACT FROM AUTHOR]

Byline: Fangwu Ma, Yongxin Men, Zixue Du To improve the vehicle ride and handling, parametric uncertainty in active suspension systems is addressed. A numerical model with parametric uncertainty is proposed and its state equations derived. Robustness analyses are carried out based on a quarter vehicle model. The H∞ controller is shown to provide the best control strategy in terms of stability and performance robustness. Optimised control approaches are studied using the quarter vehicle application. The effects of parameter variation are examined in frequency and time domains. The results show that H∞-based control is the best with regards to body acceleration, dynamic tyre deflection and suspension deflection.

In order to master the main malfunction and the law of occurrence of the vehicle which affects the operational reliability of the Straddle-Type Monorail traffic, this paper, based on the structural characteristics of monorail vehicle system and the statistical data of vehicle operational malfunction, uses the analysis method of system reliability engineering to study and determine the key factors that affect the operational reliability of monorail vehicle. Then, the operational reliability evaluation index system of monorail vehicle is established based on the influencing factors. Finally, the AHP (Analytic Hierarchy Process) method is used to determine the weights of each index, and the fuzzy comprehensive evaluation method is used to evaluate the operational reliability of monorail vehicle synthetically. The evaluation results have some guidance on the development of more effective maintenance strategies for monorail vehicle maintenance departments. [ABSTRACT FROM AUTHOR]