地震作用下 CFG桩复合地基动力特性分析

应用Biot固结方程建立动力方程，采用有限元的方法，对地震荷载作用下CFG桩复合地基进行二维动力分析。研究结果表明：复合地基的加速度在6s时的最大峰值有所提高，说明CFG桩的存在对整个地基来说是有利的。随着桩长的增加，最大加速度逐渐提高，但当桩长为12m时，与桩长为9m时相比．加速度变化幅度不大。     

五连杆非独立后悬架弹性转向特性

为研究五连杆非独立后悬架车辆的操纵稳定性,建立了含后轴弹性转向的线性三自由度操纵稳定性整车模型,运用频域法研究了后轴弹性转向对整车不足转向性能的影响.结果表明:左、右上拉杆的交点相对后轴中心的纵向位置及上拉杆衬套的刚度影响整车的不足转向特性.当上拉杆交点位于后轴之后1.65 m及上拉杆衬套的扭转刚度为1.5 kN.m/rad时,整车的不足转向特性较理想.试验与理论模型仿真结果趋势一致.     

Overview of intelligent ship route optimization methods北大核心CSCD

智能船舶航线优化在学术界和工业界均受到越来越多的关注。针对智能船舶航线优化问题,从航线设计方法和航线优化算法这2个层面,分别阐述各种设计方法和优化算法的特点。结合近5年来的最新研究成果,在分析国内外智能船舶航线优化技术发展现状的基础上,将航线设计方法归纳为3种,即基于气象数据的航线优化、基于油耗模型的航线优化以及基于航线库或航路点库的航线优化,剖析其技术内涵及应用情况;深入分析改进的等时线法、动态规划法、图形搜索算法、智能算法、人工智能和机器学习算法的特性及不足,总结归纳将各类算法应用于智能船舶航线优化时存在的主要问题。最后,简要展望智能船舶航线优化的发展趋势,为未来在该领域的研究提供一定的思路。     

汽车操纵动力学十八自由度模型仿真研究

本文介绍了根据多刚体动力学中的凯恩方法建立的一般两轴汽车的十八自由度数学模型。     

大跨度斜拉桥摩擦摆式支座减震性能分析

为选用合适的摩擦摆支座设置方案,以改善地震作用下大跨度斜拉桥下部结构的受力性能,以安庆-九江高铁鳊鱼洲长江大桥主航道桥为背景,利用有限元软件建立全桥模型,比较不同摩擦摆支座设置方案下桥梁下部结构的地震反应。结果表明:在地震作用下,不设置摩擦摆支座时,承台底轴力及墩梁之间相对横向位移不满足减震要求;仅边墩设置摩擦摆支座墩梁之间相对横向位移不满足设计要求;边墩及辅助墩均设置摩擦摆支座后,下部结构最不利轴力显著提高,墩梁之间相对横向位移响应明显下降,安全系数大幅提高,均能满足结构减震要求。鳊鱼洲长江大桥主航道桥最终采用边墩及辅助墩均设置摩擦摆支座方案。     

Foldable container in empty container repositioning in intermodal transportation network of Belt and Road Initiative: strengths and limitations

In 2013, the concept of the ‘Silk Road Economic Belt and the 21st-Century Maritime Silk Road (Belt and Road)’ was initiated by the Chinese government, which involves Asian, European and African continents and their adjacent seas. Logistics plays a core role in such a large framework of economy and trade. In recent years, China, European Union, and Southeast Asia pay much attention to the design and development of the intermodal transportation network towards both economic and environmental efficiency. In this paper, we propose an empty container repositioning model in the intermodal transportation network of Belt and Road (B&R) Initiative by considering both standard and foldable containers. In this model, empty containers are repositioned from the inland of the original area, such as China, to other areas of B&R Initiative related countries and regions, such as European Union and Southeast Asia. We develop a mixed integer linear programming model to determine the optimal repositioning of empty containers via the intermodal transportation network. An Artificial Bee Colony algorithm is developed to solve large size problems in practice and numerical experiments are conducted to show the efficiency of our proposed algorithm. We provide managerial insights regarding the impact on the network performance of foldable containers transportation.     

Disaster prevention and strategic investment for multiple ports in a region: cooperation or not

With the growth of maritime transportation, seaports have become critical to the world economy as linking nodes between shipping and inland transport. However, the port system is fragile under certain unconventional emergency events. This study addresses the issue of investment on disaster prevention within the port competition context. The present model discusses and compares four situations of different relationships and strategies of pre-disaster prevention between two adjacent ports. Results indicate that both ports increase the disaster prevention investment under the cooperation scenario compared with that in the case of non-cooperation wherein they are complementary ports. Meanwhile, a numerical simulation is conducted to examine the collective and individual rationality of both ports. Although cooperation strategy decreases the total risk cost of two ports, one of the two ports may profit, whereas the other may suffer losses.     

计算流体动力学(CFD)在配管中的应用

随着软件技术的发展,计算流体动力学(CFD)在炼油化工行业中得以应用。文中以计算流体动力学模拟软件FLUENT为例,详细描述了利用计算流体动力学方法优化分支配管结构,结果表明CFD方法能够科学直观地解决此类配管优化问题,有着广泛的应用前景。     

输入多采样率数字控制系统的鲁棒极点配置

讨论了输入多采样率状态反馈鲁棒极点配置问题。由于输入多采样率采样,增加了系统的实际输入的个数,使得实现极点配置的状态反馈控制系统中具有自由度。现将这一自由度明确地表示为自由参数的形式,并利用优化算法选择这些参数,增强闭环系统的鲁棒性。     

旭普林无砟轨道路基施工研究

系统地阐述了德国旭普林无砟轨道（双块式轨枕）在路基上施工的工艺和技术方案,对同类型的路基施工具有重要参考价值。