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571.
Shunhua Zhou Honggui Di Chao He 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2018,56(12):1945-1968
An accurate evaluation of the metro train-track-tunnel-soil dynamic interactions is very important in engineering practice. Therefore, an innovative train-track-tunnel-soil vertical coupled model was established to calculate the train-induced dynamic response of the system based on the integration of the substructure method and the semi-analytical approach. The modelling of each subsystem was presented, including the multi-rigid model of the train subsystem, the beam model of the track subsystem and the semi-analytical model of the tunnel-soil subsystem. The wheel-rail contact theory, the fastener force model and the displacement compatibility conditions were used to determine the dynamic interactive relationship between the subsystems. An explicit integral approach was used in the proposed model to analyse the complex system in the time domain which was capable of modelling highly nonlinear loading behaviours of the train-track-tunnel-soil system. The proposed model was validated by comparing with the vehicle-track coupled dynamics software VICT, the Pipe-in-Pipe model and the measured data from the onsite test in the tunnel of Ningbo Metro line 2. An illustrative example of the model was then presented to display the dynamic responses of the tunnel system under the passage of a metro train. 相似文献
572.
Objective: Vehicle-to-vehicle (V2V) communication has become one of the most active fields of research recently. The implementation of the wireless connected vehicles has widely extended the transmission range of warning messages to inform drivers of hazards ahead. The present study addressed the human component with mathematical modeling of the human reaction time to warning messages in the connected vehicle systems (CVSs) with different confidence intervals (CIs). Methods: In the present study, human performance in warning responses is modeled by extending an existing mathematical model of human performance with the complexity level of tasks. The modeling of human performance with different levels of uncertainty is integrated to propose the warning message notification model in the CVS settings. The warning message notification models were proposed to model the CVSs parameters including maximum available message notification delay, the maximum available machine processing time, the minimum acceptable message notification range, and the designed message display delay. Results: The optimal designs of CVSs parameters were presented in general and for specific conditions by applying the modeling of human performance with different CIs (i.e., 95% and 99% CI) and the warning message notification model with human in the loop. A software interface with the message notification model implemented was presented to discuss the practical benefits of the current work in the design of CVSs. 相似文献
573.
Toshifumi Fujiwara Grant E. Hearn Fumitoshi Kitamura Michio Ueno Yoshimasa Minami 《Journal of Marine Science and Technology》2005,10(3):131-146
The steady sailing performance of a sail-assisted bulk carrier is investigated utilising towing-tank derived hydrodynamic derivatives and wind tunnel measured aerodynamic properties of the sails and the ship. The aerodynamic characteristics investigated include the ship hull at the fully-loaded draught, the sail–sail interaction effects for two sets of four identical hybrid-sails, and the sail–hull interaction effects for the same two sets of identical sails in the presence of the selected bulk carrier hull-form. This is in addition to lift–drag measurements of single isolated sails of each shape. The form of the two sets of soft sails was rectangular and triangular. This paper is concerned with assessing the benefits of a sail-assisted ship operation, and hence a steady-state rather than complete time-domain integrations of the governing equations are reported. The results of the completed analysis suggest that the benefits of the derived sail generated driving force are greater than the overhead of equipping the ship with a selected system of hybrid-sails. Sail-assisted ships could represent an important contribution to an improving global environment by reducing the demands for a driving force through the propeller. 相似文献
574.
两船在波浪中耦合运动的三维频域理论研究 总被引:4,自引:0,他引:4
本文采用三维势流理论求解两船在波浪中相互干扰的耦合运动。基于源分布方法,两船船体表面被划分成若干面元,在每一面元上进行等源强分布。为了验证该理论以及算法的可行性,计算了有限水深中两圆柱的水动力干扰,其数值计算结果与其他理论结果吻合较好。其次计算了两船在波浪中无航速与有航速情况的水动力干扰,其结果与单船结果以及双船试验结果进行比较。同时深入研究了纵横向间距以及航速变化对水动力干扰的影响,得出间距与航速不仅是水动力干扰的重要参数,而且对两船中的小船影响尤为重要。本文的研究提出了一种有效而又简单的方法预报两船在波浪中的耦合运动,为分析海上航行补给所涉及的水动力问题提供了有效的手段。 相似文献
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577.
In order to improve the safety properties of an offloading system with side-by-side (SBS) mooring in which the FPSO is moored by a yoke system in the field of BZ25-1, it is necessary to analyze those properties. According to the experience of similar projects, tow strategies of different offloading arrangements were discussed by using the 3-D radiation/diffraction theory and quasi-static time domain method to assess their respective safety properties. Through the safety assessment analysis of different arrangement comparisons, various ways to improve the safety properties of offloading systems with side-by-side mooring were verified by analyzing the tension in the mooring lines and the fender deflection. Through comparison it can be concluded that by enlarging the key factors properly, including the size of the fenders and the hawsers as well as the number of hawsers, a better safety performance can be achieved. 相似文献
578.
微型桩具有诸多施工优势,近年来正不断推广应用于滑坡治理工程,并取得了较好的工程效果。为了求解桩的内力,按横向约束的弹性地基梁法提出了内力计算方法,并结合模型试验,得出了较为合理的计算结果,为微型桩的工程应用提供一种可行的理论依据。 相似文献
579.
580.
孙菲 《武汉船舶职业技术学院学报》2014,(3):66-68
本文主要探讨了信息时代大环境下,通过加强图书馆藏书建设、规范管理及开展创新服务、做好效果检验等几方面的工作,积极推动高职院校图书馆服务创新,为提高高职院校人才培养质量服务。 相似文献