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张继光 《城市轨道交通研究》2017,(12):66-69
现代有轨电车线路多沿地面敷设,与道路平面交叉。为提高有轨电车通行效率,应在平交路口给予有轨电车优先通行权。结合苏州高新区有轨电车1号线的实际情况,分析并比较了有轨电车平交路口信号优先控制方案。详细描述了实时交互式方案的设计。实时交互式方案的灵活性、适用性好、安全性高,其控制策略易调整,便于管理,能较好地满足相关需求。 相似文献
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宋剑伟 《城市轨道交通研究》2021,24(4):26-29
针对城市轨道交通信号系统测速定位,详细分析了常用的轮轴速度传感器、多普勒雷达及加速度计的测速原理,并深入分析了各传感器的误差影响因素、失效模式以及传感器的复杂性.对目前常用的4种组合测速定位方案,从方案的测量精度、成本、系统可靠性、设备安装、安全性评估等方面进行了分析比较,给出了各种测速定位方案的优缺点.分析比较结果表... 相似文献
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In various engineering fields like aerospace and aircraft structures or marine and offshore platforms, constitutive material of critical components should be made of specific materials that can work properly in the required workspace. Such materials must have excellent properties such as high mechanical strength as well as great resistance to corrosion, oxidation, and creep. Inconel 625 is a superalloy that is chosen as constitutive material of critical components due to its great abilities. On the other hand, since investigating Inconel 625 pipe has not been done yet, different mechanical characteristics of using structures made of Inconel 625 should be assessed. Additionally, doing so would be necessary to gather information for current industrial affairs and also future investigations. Therefore, the nonlinear dynamic instability response of axially loaded Inconel 625 pipes is investigated in the current article. The pipe structure is modeled via the Donnell shell theory and nonlinear von Kármán theory. The motion equations of pipes are established by applying the Hamiltonian approach. Then, in order to alter the nonlinear derived partial differential equations into the Mathieu-Hill equation, both Navier's solution and Airy stress function are implemented. Additionally, the amplitudes of steady-state oscillation of the Inconel 625 pipe are determined by employing Bolotin's method. Eventually, the impacts of various effective parameters on the nonlinear dynamic behaviors of Inconel 625 pipes are evaluated. The results indicate static and dynamic load factors possess a remarkable effect on instability exciting areas and steady-state vibration amplitudes of pipe. Moreover, the dynamic instability response of the pipe is dependent on the radius-to-thickness and length-to-radius ratios, and also how the ratios are affected depends on the wave number. 相似文献
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In order to release the axial compressive force resulting from high-temperature conditions, sleepers or distributed buoyancy sections are usually installed along the route of the subsea pipeline as the buckle initiation facilities to trigger lateral buckles. DNV-RP-F110 suggests that the individual buckle initiators can be combined to further increase the reliability of buckle formation. In this study, an improved buckle initiation technique, called the combined sleeper and distributed buoyancy section, is investigated. A generalised mathematical model is proposed to simulate lateral buckling triggered by the combined sleeper and distributed buoyancy section, and it can also be applied to simulate lateral buckling triggered by an individual technique, such as triggered only by sleeper or only by distributed buoyancy section. The mathematical model is verified by comparing with the solutions in the literature. The parametric analysis shows that the buckle formation reliability can be improved when the combined sleeper and distributed buoyancy section is employed. Moreover, both the axial force and the maximum stress along the buckled pipeline in the post-buckling stage are at a lower level, so the pipeline will be safer when the combined sleeper and distributed buoyancy section is utilised as the triggers. 相似文献
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[Objective]Aiming at the problem of too many influencing factors and too little reference data for determining the dimensions of medium-sized cruise ships in the concept phase, a simplified multi-objective optimization method based on the fitting of dimensions and performance is proposed. [Method]First, the dimension relations of medium-sized cruise ships are analyzed and the influence of the latest SOLAS requirements used to determine the optimization range. Second, the influence of cruise ship dimensions on space, resistance, stability and seakeeping are analyzed. Next, based on the principles of genetic algorithms, a multiobjective optimization algorithm with high robustness and high engineering adaptability is determined to establish a multi-objective optimization model for the concept design of medium-sized cruise ships. Finally, the Pareto solution obtained by multi-objective optimization is analyzed to provide initial references for determining the dimensions of the target cruise ship. [Results]Implemented via a genetic algorithm, the optimization program proposed herein is applied in the concept design of a medium-sized cruise ship in order to optimize the initial dimensions, thereby achieving the expected outcome of providing reasonable initial dimensions for cruise ship design. [Conclusion ] The proposed simplified multi-objective optimization model can provide feasible initial dimensions for medium-sized cruise ships in the concept phase. As the Pareto solution obtained by multi-objective optimization has different focuses such as resistance and stability, the most suitable solution needs to be selected according to the design object. © 2023 Chinese Journal of Ship Research. All rights reserved. 相似文献
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