High-speed Railway最新文献

Modal and damage identification based on ambient excitation can greatly improve the efficiency of high-speed railway bridge vibration detection. This paper first describes the basic principles of stochastic subspace identification, peak-picking, and frequency domain decomposition method in modal analysis based on ambient excitation, and the effectiveness of these three methods is verified through finite element calculation and numerical simulation. Then the damage element is added to the finite element model to simulate the crack, and the curvature mode difference and the curvature mode area difference square ratio are calculated by using the stochastic subspace identification results to verify their ability of damage identification and location. Finally, the above modal and damage identification techniques are integrated to develop a bridge modal and damage identification software platform. The final results show that all three modal identification methods can accurately identify the vibration frequency and mode shape, both damage identification methods can accurately identify and locate the damage, and the developed software platform is simple and efficient.

High-speed Electromagnetic Suspension (EMS) train is continuously impacted by the irregularity of the track, which worsens the levitation performance of the train. In this paper, a composite control scheme for the EMS is proposed to suppress track irregularities by integrating a Refined Disturbance Observer (RDO) and a Prescribed Performance Fixed-Time Controller (PPFTC). The RDO is designed to estimate precisely the track irregularities and lumped disturbances with uncertainties and exogenous disturbances in the suspension system, and reduce input chattering by applying to the disturbance compensation channel. PPFTC is designed to converge the suspension air gap error to equilibrium point with prescribed performance by completing error conversion, and solve the fast dynamic issue of EMS. And the boundary of overshoot and steady-state is limited in the ranged prescribed. A theoretical analysis is conducted on the stability of the proposed control method. Finally, the effectiveness and reasonability of the proposed composite anti-disturbance control scheme is verified by simulation results.

The high-speed railway construction involves multiple professional fields, such as railway design, construction, and supervision. This paper architects the "BIM+ " project refined management platform, designs the platform's logical architecture, physical architecture, and solves several key technology difficulties. This "BIM+ " platform has been applied on the Jingxiong Bridge Project and achieved all-round, whole-process and multi- management of high-speed railway engineering construction. It significantly improves the level of construction management, and plays a role in promoting the development of high-speed railway construction informatization.

At present, BIM platforms rely on foreign software. Homemade software and industry applications are mostly secondary developments, which present stranglehold problems caused by interruptions to the software supply. To solve the problem, key technical research on the 3D integrated design of railway engineering was stuedied based on homemade graphics engines to propose an innovative railway BIM platform framework. The entire process was completed from the top-level design to the engineering verification of the platform. The co-designed mechanism of a "center model and link" hybrid mode was constructed, which solved the difficulties of data management and increment synchronization at a large scale, achieving teamwork among surveying and mapping, alignments, and bridges. The results of this study could provide strong support for the development of BIM software for a whole railway and all majors.

This study addresses the comparative carbon emissions of different transportation modes within a unified evaluation framework, focusing on their carbon footprints from inception to disposal. Specifically, the entire life cycle carbon emissions of High-Speed Rail (HSR), battery electric vehicles, conventional internal combustion engine vehicles, battery electric buses, and conventional internal combustion engine buses are analyzed. The life cycle is segmented into vehicle manufacturing, fuel or electricity production, operational, and dismantling-recycling stages. This analysis is applied to the Beijing-Tianjin intercity transportation system to explore emission reduction strategies. Results indicate that HSR demonstrates significant carbon emission reduction, with an intensity of only 24 %–32 % compared to private vehicles and 47 %–89 % compared to buses. Notably, HSR travel for Beijing-Tianjin intercity emits only 24 % of private vehicle emissions, demonstrating the emission reduction benefits of transportation structure optimization. Additionally, predictive modeling reveals the potential for carbon emission reduction through energy structure optimization, providing a guideline for the development of effective transportation management systems.