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The suspended monorail (SM) vehicle–bridge system has been considered a promising modern transit mode due to its clear advantages: low pollution, high safety, convenient construction, and low cost. The wind-induced response can significantly affect the running safety and comfort of this type of vehicle due to its special suspended position from a fixed track. This study is the first to systematically investigate its aerodynamic characteristics and interference effects under various spacing ratios using wind tunnel tests and numerical simulations. A high level of agreement between the wind tunnel test and CFD (computational fluid dynamics) results was obtained, and the aerodynamic interference mechanism can be well explained using the CFD technique from a flow field perspective. A wireless wind pressure acquisition system is proposed to achieve synchronization acquisition for multi wind pressure test taps. The paper confirms that (1) the proposed wireless wind pressure acquisition system performed well; (2) the aerodynamic coefficients of the upstream vehicle and bridge were nearly unchanged for vehicle–bridge combinations with varying spacing ratios; (3) the aerodynamic interference effects were amplified when two vehicles meet, but the effects decrease as the spacing ratio increases; (4) the aerodynamic force coefficients, mean, and root mean square (RMS) wind pressure coefficients for the downstream vehicle and bridge are readily affected by the upstream vehicle; (5) the vortex shedding frequencies of vehicles and bridges can be readily obtained from the lift force spectra, and they decrease as the spacing ratio increases; and (6) a spacing ratio of 3.5 is suggested in the field applications to ensure the running safety and stability of the SM vehicle–bridge system under exposure to crosswinds.

Variable speed operation of the train cause easily the wheel-track slipping phenomenon, inducing strong nonlinear dynamic behavior of the suspended monorail train and bridge system (SMTBS), especially under an insufficient wheel-track friction coefficient. To investigate the coupled vibration features of the SMTBS under variable speed conditions, a novel 3D train–bridge interaction model for the monorail system considering nonlinear wheel-track slipping behavior is developed. Firstly, based on the D’Alembert principle, the vibration equations of the vehicle subsystem are derived by adequately considering the nonlinear interactive behavior among the vehicle components. Then, a high-efficiency modeling method for the large-scale bridge subsystem is proposed based on the component mode synthesis (CMS) method. The vehicle and bridge subsystems are coupled with a spatial wheel-track interaction model considering the nonlinear wheel-track sliding behavior. Furtherly, by a comprehensive comparison with the field test data, the effectiveness of the proposed method is verified, as well as the reasonable modal truncation frequencies of the bridge subsystem are determined. On this basis, the dynamics performances of the SMTBS are evaluated under different initial braking speeds and wheel-track interfacial adhesion conditions; besides, the nonlinear wheel-track slipping characteristics and their influences on the vehicle–bridge interaction are also revealed. The analysis results indicate that the proposed model is reliable for investigating the time-varying dynamic features of SMTBS under variable train speeds. Both the axle load transfer phenomenon and longitudinal slip of the driving tire would be easy to appear under the braking condition, which would significantly increase the longitudinal vehicle–bridge dynamic responses. To ensure a good vehicle–bridge dynamics performance, it is suggested that the wheel-track interfacial friction coefficient is larger than 0.35.

This paper focuses on parameter optimization for the actually manufactured test vehicle. This method achieves high-precision, rapid computation of vehicle dynamic performance while fully preserving the strongly coupled nonlinear dynamic properties of the system. Firstly, by employing twin modeling technology, the model accurately reflects the physical dynamic characteristics of the actual vehicle, enabling us to determine how much improvement the optimized vehicle dynamic response will exhibit compared to the current state. Next, a mathematical model for multi-parameter, multi-objective collaborative optimization is constructed using big data search, and key parameters significantly influencing vehicle dynamics are identified through Sobol sensitivity analysis for dynamic optimization. Finally, an improved multi-start parallel simulated annealing algorithm is proposed to enhance the computational efficiency and reliability of the optimization results. The results demonstrate significant improvement in the dynamic performance of the experimental vehicle, validating the effectiveness of the proposed method. This approach overcomes the limitations of traditional linearization treatments, providing a new perspective for dynamic optimization of complex coupled systems and demonstrating significant engineering application value in the field of rail transportation.

The method of increasing the efficiency of using one of the most common means of auxiliary transport in underground coal mines—suspended monorails—is presented. Increase of velocity is one of the key parameters to improve the efficiency and economical effect related with the underground auxiliary transport. On the other hand, increasing the velocity results in bigger value of force acting on the suspended monorail route and its suspensions. The most important issue during increasing the velocity is ensuring the required safety for the passengers and not overloading the infrastructure. In order to analyze how increasing velocity influences the level of loads of the route suspension and the steel arch loads, the computational model of suspended monorail was developed. The computational model included both the physical part (embedded in the program environment based on the Multi-Body System method) and the components of the monorail control system. Two independent software environments were cooperating with each other through the so-called co-simulation. This model was validated on the base of results obtained on the test stand. Then, the numerical simulations of emergency braking with different values of velocity were conducted, which was not possible with the use of physical objects. The presented study can be used by the suspended monorail’s producers during the designing process, and leads to increase the safety on underground transportation routes.

Transporting materials and mine staff is a vital link necessary to the production process in underground mines. Deteriorating climatic conditions, mainly due to the increasingly deep mining and the usage of machines, force us to look for solutions to improve the underground mine environmental situation. Another essential factor responsible for deteriorating working conditions is harmful substances and exhaust fumes emitted from diesel engines. Supplying the workplaces with air quantity exceeding requirements such as the minimum velocity of air movement or gas and climatic conditions will allow for maintaining the gas concentration at the appropriate level. One possible way to solve the problems mentioned above is to replace suspended monorails powered by internal combustion engines with new solutions of electrically battery-powered monorails. Electric monorails are not yet widely used in mines; nevertheless, they have many advantages. This article analyzes the exhaust gas parameters from monorail locomotives operating in a hard coal mine and determines the required airflow to maintain permissible concentrations of harmful gases. It also focuses on a comparative analysis of climatic conditions in the development heading, considering the roadway’s functioning with and without using diesel or electric monorail. The study consists of the methodology for predicting climate conditions. Based on the performed analysis, it was shown that using electric monorails could significantly improve working conditions.

The article presents recommendations that should be followed by the manufacturers of underground mine suspended monorail transportation means (auxiliary mine transport equipment), used on inclinations up to 45 degrees, in the context of using the technical data contained in the instructions for their entry into the Safe Trans Design (STD) database. Safe Trans Design system was developed by KOMAG Institute of Mining Technology in 2013. At the same year it was implemented in the mines of Jastrzębska Coal Company (JSW S.A.). Its purpose is to help (assist) designers of suspended monorail transportation system to carry out traction calculations. These calculations are required in the process of preparing documentation for the transportation system. Technical data included in the database, should contain information for: suspended monorail locomotives, brake trolleys, modular carrying sets (high-load beams), sets of hoists, cabins, and benches for movement of people, containers, and special wagons. Examples of generalized input data for the selected components of the suspended transportation unit (passenger cabin and suspended locomotive), in the context of their use in traction calculations, are presented. An example of importing the graphical load-carrying characteristic for suspended monorail locomotive, using digitalization and the CAD system (AutoCAD), is also presented.

A suspended monorail transit system is a category of urban rail transit, which is effective in alleviating traffic pressure and injury prevention. Meanwhile, with the advantages of low cost and short construction time, suspended monorail transit systems show vast potential for future development. However, the suspended monorail has not been systematically studied in China, and there is a lack of relevant knowledge and analytical methods. To ensure the health and reliability of a suspended monorail transit system, the driving safety of vehicles and structure dynamic behaviors when vehicles are running on the bridge should be analyzed and evaluated. Based on the method of vehicle-bridge coupling vibration theory, the finite element method (FEM) software ANSYS and multi-body dynamics software SIMPACK are adopted respectively to establish the finite element model for bridge and the multi-body vehicle. A co-simulation method is employed to investigate the vehicle-bridge coupling vibration for the transit system. The traffic operation factors, including train formation, track irregularity and tire stiffness, are incorporated into the models separately to analyze the bridge and vehicle responses. The results show that the coupling of dynamic effects of the suspended monorail system between vehicle and bridge are significant in the case studied, and it is strongly suggested to take necessary measures for vibration suppression. The simulation of track irregularity is a critical factor for its vibration safety, and the track irregularity of A-level road roughness negatively influences the system vibration safety.

The development of monorail transport systems began relatively recently, though their history dates back to the early 19th century. In modern hard coal mining, a suspended monorail is a basic means of auxiliary personnel and material transportation. A project with the acronym HEET II is currently being carried out as part of the European Union’s Research Fund for Coal and Steel. One of the elements of the transport system developed as part of the project is the composite steel rail that constitutes the subject of this publication. The innovative rail design serves as the runway for the suspended monorail and an element of its power supply system. This paper supplements a certain research gap or rather undertakes the first attempt at testing a railway track formed from composite-steel rails consisting of a composite section in the middle, similar in shape to an I-beam, as well as two steel joints constituting the ends for mounting further rails and for coupling with the hoists. It presents the methodology and results of composite-steel rail testing under static and cyclic fatigue loading and prolonged bending loading applied to the rail during a creep test. It also presents the results of comparative tests for the composite steel rail and a conventional steel rail during overloading and break tests under bending loading. The composite-steel rail test methodology was significantly expanded relative to the conventional steel rail methodology, given that the composite materials and resins are strongly susceptible to creeping, and their operation under cyclic loads exhibits a greater risk of failure compared to steel rails. The composite-steel rail test results presented in this article make it possible to conclude that despite its existing design flaws, applying this type of rail design in underground suspended monorail transportation cannot be excluded.

Urban transportation systems are facing severe challenges due to the rapid growth of the urban population, especially in China. Suspended monorail system (SMS), as a sky rail transportation form, can effectively alleviate urban traffic congestion due to its independent right-of-way and minimal ground footprint. However, the SMS possesses a special traveling system with unique vehicle structure and bridge configuration, which results in significant differences in both the mechanisms and dynamics problems associated with train–bridge interaction (TBI) when contrasted with those of traditional railway systems. Therefore, a thorough understanding of the SMS dynamics is essential for ensuring the operational safety of the system. This article presents a state-of-the-art review of the TBI modeling methodologies, critical dynamic features, field tests, and practice of the SMS in China. Firstly, the development history, technical features, and potential dynamics problems of the SMS are briefly described, followed by the mechanical characteristics and mechanisms of the train–bridge interactive systems. Then, the modeling methodology of the fundamental elements in the suspended monorail TBI is systematically reviewed, including the suspended train subsystem, bridge subsystem, train–bridge interaction relationships, system excitations, and solution method. Further, the typical dynamic features of the TBI under various operational scenarios are elaborated, including different train speeds, a variety of line sections, and a natural wind environment. Finally, the first new energy-based SMS test line in the world is systematically introduced, including the composition and functionality of the system, the details of the conducted field tests, and the measured results of the typical dynamic responses. At the end of the paper, both the guidance on further improvement of the SMS and future research topics are proposed.

Nowadays designing of selected areas of mines underground workings can be effectively improved by numerical simulation. This, in fact, would result in the more reliable design process, significantly reduced designing costs and efforts, and improvement of the mines staff’s safety. Mine transportation of materials and people in underground workings is realized by use of mine railway system (on the main transportation routes), floor-mounted railway and suspended monorail (in a department transportation). Transportation is realized on tracks placed on the floor of working (floor-mounted rail transportation, using transportation platforms) or on rails suspended to roadway support (suspended rail transportation, using modular carrying sets (high-load beams)). The increasing size and weight of the transported machines and other equipment require planning the transportation system based on analyses of transportation routes as regards possibility of collision between transported loads and roadway support components, the equipment or other machines, that can be the obstacles or that can cause hazard during transportation, to select properly transportation machines. In case of improper selection, this may be the reason of hazard during transportation (dynamic impact of a mass of several tons). The developed method involves two-pronged generation of input data for collision analysis in a CAD software environment. Data regarding the route and constraints resulting from the dimensions of the roadway excavation are transferred in a CAD file format. Data regarding the overall dimensions of the means of transport (suspended monorail or floor-mounted railway) and simulation parameters are developed in a dedicated software environment in the form of a website. The methodological assumptions of the problem are presented, and its implementation into CAD software (AutoCAD) environment is given. Finally, an example of the application of the described method to analyze collision possibility during transportation operations, using floor-mounted railways and suspended monorails, during transportation of big-size load is given (transportation of longwall powered roof support). Developed software is used in Jastrzębska Coal Company S.A. as a Safe Trans Design, by the designers of transportation systems, during the verification of transport system designs, against safety criteria.