Design of Heavy Agricultural Machinery Rail Transport System and Dynamic Performance Research on Tracks in Hilly Regions of Southern China

In situ evaluation of dynamic characteristics of prefabricated ballastless track slab using EMA and OMA techniques

Rapidly rising economies and urbanization have immensely increased the energy concerns in transportation sector. The road transportation system is unable to provide long-term solutions to these problems due to raging fuel prices, rising environmental concerns, and worsening traffic congestion as a result of the increasing private vehicle ownership. Thus, to improve the energy security in this sector, emphasis must be given to the development of mass rail transit systems. The actual challenge lies in developing such rail transit systems that can reduce the dependency on road transport with lesser carbon footprints. However, conventional rail transit systems based on rotary motors possess many limitations in terms of speed, efficiency, automation, and sustainability. The development of a linear motor-based high-speed rail transportation system can provide a viable solution to these problems. The use of linear motors in these systems offers many advantages as compared to rotary motor-based conventional rail transportation systems. Being fully electrified, such a system also decreases the dependency on oil products making it a greener and more contemporary alternative to conventional rail transportation systems. This chapter gives a basic understanding of high-speed rail transportation systems. It describes the various constituents of high-speed rail transportation systems in detail, with a focus on the advancement attained by different countries in this technology, to make the system efficient and sustainable. This chapter also highlights the relevance of linear motor-based high-speed rail transit systems in today’s scenario. A comparison of these technologies to analyze their applicability in context with India is also discussed.

Enhancing reliability in estimating modal parameters for automotive disk Brakes: A comprehensive approach using the Eigensystem Realization algorithm and additional criteria

Structure modal parameter online identification was used to monitor the structural health as evidenced by changes in the vibration characteristics. The natural excitation technique and the eigensystem realization algorithm were combined to identify the modal parameters in the time domain of a structure excited by simulated ambient vibrations. The mass-normalized mode shapes were obtained from the eigen-sensitivity analysis. The experimental modal analysis was performed on a two-story steel braced frame model excited by simulated ambient vibrations and hammer impacts. The mass-normalized mode shapes were acquired by changing the structural mass and by eigen-sensitivity analysis. From finite element analysis results and the experimental data, it is shown that this method is effective.

In order to improve the dynamic performance of the grinding machine and improve the machining precision of the machine tool, a modal experiment is conducted on the complete machine and main sub-structures of the series-parallel hybrid grinding and polishing machine tool according to the basic theory of experimental modal analysis. Also, hammer impulse excitation and varied-time-based sampling methods are adopted to perform experimental modal analysis. Meanwhile, the eigensystem realization algorithm (ERA) is utilized to identify modal parameters, so that the low-order natural frequency, damping ratio and modal shape of the complete machine and its main substructures can be obtained. Based on the analysis of frequency and vibration mode, the beam is a weak link of the machine tool, while an approach to improve the dynamic characteristics of the machine tool structure is proposed to provide a basis for the optimized design of dynamics.

In the engineering background of the prototype test of a deep radial gate on three gorges dam, two methods are provided for the modal parameter identification of the radial gate, one is applying operation modal analysis (OMA) to a gate which is under flood discharge, the other one is applying experiment modal analysis (EMA) to a inactive gate with some other gates under flood discharge. This paper is based on the feasibility study on the former method. We use the natural excitation technology (NExT) combined with the eigensystem realization algorithm (ERA) to determine the dynamic characteristics of a gate. Displacement data at 7 locations were processed using NExT-ERA to extract the natural frequency and associated damping ratio. The results show the effectiveness of this modal identification methodology and the possibility of implementing it on other hydraulic structure.

Deficiencies in present methods of reporting multiple-response data in clinical trials: Some alternatives

On the problem of stochastic experimental modal analysis based on multiple-excitation multiple-response data, part I: Dispersion analysis of continuous-time structural systems

Single European Sky and Single European Railway Area: A system level analysis of air and rail transportation

Rail transportation systems often encounter risks, such as failure and downtime. Resilience engineering (RE) enables hazard-prone systems to remain stable in the face of sudden changes or to minimize the effects of changes in such systems. In other words, RE keeps the system stable in the face of any potential disturbances. This study uses a new framework, i.e. the combination of four key variables, namely health, safety, ergonomics, and resilience engineering to assess the performance of a railway transportation system. To this end, a questionnaire was first designed based on the stated concepts for data collection and performance evaluation of Tehran–Karaj railway electrification system. Then, data envelopment analysis (DEA) approach was used to evaluate the decision-making units (DMUs) of the railway system. The results indicated that there was a significant growth in the number of efficient DMUs (67%) and a relative growth in the mean value of total efficiency (3.6%) by considering RE concept. In other words, RE plays a significant role in the promotion of system performance. The results also showed that teamwork had the highest impact on the railway system performance among the RE-associated factors. The Spearman test was performed to validate the results of this study. It is one of the first studies that evaluate a railway transportation system by considering resilience engineering and other concepts, such as health, safety, and ergonomics using DEA approach.

Modifying the ERA and fast ERA to improve operational performance for structural system identification

Increased economic activity in South Africa has put pressure on both rail and road transportation systems. In particular, there is a need to increase loading on the rail systems. The railway network consists of a number of steel bridges approaching the end of their design life. The fitness of these bridges to carry higher loads needs to be assessed. The present paper describes a systematic procedure for the condition assessment of a 100 year old wrought iron railway bridge. Experimental modal analysis techniques were used to calibrate the finite-element model. The calibrated model was used to predict the behaviour of the bridge under proposed loading regimes. Strain measurements were taken at selected locations and were used to assess the fatigue life of the bridge. This work demonstrates the effectiveness of combining experimental modal analysis with actual structural response from live loading for condition assessment and performance prediction.

Operational Tests of a Full Scale Superconducting MagLevehicle Unit

Rail transportation plays a crucial role in reducing carbon emissions from the transportation system, making a significant contribution to environmental impact mitigation due to the efficiency of passenger and freight rail transportation. Accurate assessment of carbon emissions resulting from rail transit is essential to quantify the positive impact of this mode of transportation on overall urban transport emission reduction. Given that measuring carbon emissions throughout the lifecycle of rail transportation involves a wide array of factors, adopting a systematic framework for analyzing these aspects is crucial. This study conducts a comprehensive review of existing research related to carbon emissions in rail transportation and its mitigation. Initially, the distinct characteristics of carbon emissions associated with rail transportation are identified, along with the complexity involved in accurately measuring these emissions. Subsequently, a comparison and analysis are conducted regarding various models for measuring carbon emissions in rail transportation. Finally, the study examines some greenhouse gas emission measurement research within the railway system. Redirecting research efforts toward measuring carbon emissions in the rail transportation system is essential to help the development of robust and effective public policies. This measure will play a crucial role in emission reduction, climate change mitigation, and the promotion of more sustainable transportation. Furthermore, the identified results propose which LCA methodology offers a valuable framework improving the quality of railway transportation emissions for future generations.

Cable and rail transportation systems are compared with mountain highways in terms of energy consumption and adequacy. Two mountain transportation plans in Utah are taken as examples for pointing towards new horizons in recreational development. General design parameters of mechanical uphill devices are listed. Methods on how to select cable and rail systems are presented based on seasonal demand and utilization. The common resistance that innovative mountain transportation systems have encountered is brought to the attention of recreation planners, mountain developers, and administrators.