A New Wheel/Rail Spatially Dynamic Coupling Model and its Verification

Based on the theory of vehicle-track coupling dynamics, a new wheel/rail spatially dynamic coupling model is established in this paper. In consideration of rail lateral, vertical and torsion vibrations and track irregularities, the wheel/rail contact geometry, the wheel/rail normal contact force and the wheel/rail tangential creep force are solved in detail. In the new wheel/rail model, the assumption that wheel contacts rail rigidly and wheel always contacts rail is eliminated. Finally, by numeric simulation comparison with international well-known software NUCARS, comparison with vehicle-track vertical coupling model, and comparison with running test results by China Academy of Railway Sciences, the new wheel/rail spatially dynamic coupling model is shown to be correct and effective.     

散装船的结构特性与安全管理对策探讨

文章通过对散装船的结构特性和避免导致结构损伤的因素进行探讨和分析,明确管理不善是影响船体结构安全的最主要的原因之一。强调管理是根本,提升管理和操作人员的专业技术和水平是关键,重在过程监控,并提出维持结构安全的管理对策。     

舰船液力偶合器稳态、动态性能研究

分析了舰船液力偶合器试验数据作为准稳态数学模型的基本数据源时的局限性，指出了人工神经网络方法解决该问题的具体思路。在给出了液力偶合器人工神经网络数学模型的具体表现形态后，文章着重介绍了液力偶合器对舰船推进系统动态特性的影响，它们是：①不同充液规律和充液率对液力偶合器接合过程动态特性的影响；②不同螺旋桨负载对液力偶合器接合过程动态特性的影响；③舰船正常加速过硅发动机下同加载速度对液力偶合器动态特性的影响。最后，文章介绍了正常航行(四机双桨)稳态工况时各柴油机转速下液力偶合器滑差的变化及其物理意义。     

质量“工具”在产品生产过程中的应用

企业为获得更为卓越的绩效成果,必须加强对质量管理的重视程度,通过提高产品质量、大幅度地降低顾客成本,提高顾客响应能力,从而获得卓越的竞争优势.质量工具是质量管理中的重要帮手,“因果图”和“排列图”最适合部门的产品业务.通过对两图之间的关系研究,将两者互补应用于生产,提高了业务质量的同时,加快了过程速度,提升了组织的竞争力.     

功能梯度输流管在弹性基体中的热弹性振动分析

为了研究嵌入弹性基体功能梯度输流管的流固耦合振动问题,首先根据欧拉梁模型理论推导得到功能梯度输流管道的振动控制方程,然后采用微分求积法对振动控制方程进行求解,最后根据计算结果详细讨论了材料组分的体积分数、温度、长细比及弹性基体的弹性系数对系统的固有频率及临界流速的影响. 研究结果表明:（1） 内部材料组分的体积分数增大会使系统的无量纲固有频率增大,临界流速减小（指数n由0增大到10,流速为0时的固有频率增大约13%,临界流速减小约6%）;（2） 随着温度的升高,系统的固有频率和其临界流速都会降低（长径比为100时,温度升高30 K,流速为0时的固有频率减小约4%,临界流速减小约14%）,减小长径比会使得系统的固有频率明显下降（长径比为100、50和20时,系统的固有频率分别为160、41.1和11.87.）;（3） 系统的固有频率随着管道外径的增大而降低,管壁越薄变化越快,管壁越厚变化越慢（外径由0.1 m增大到0.11 m时,其固有频率的下降幅度约为外径由0.19 m增大到0.2 m时的100倍）;（4） 弹性基体弹性系数k增大会提高系统的固有频率（k增大3倍,系统的固有频率提高了约74%）.      

A new GPS deformation monitoring algorithm applied to Donghai Bridge

A real-time, long-round global positioning system (GPS) bridge-deformation monitoring technology was proposed, which processes the carrier phase of multiple GPS receivers in an operation center. It was demon- strated an extended Kalman filter with triple differential ionospheric-free measurement (EKF-TIF) which can eliminate the ionospheric delay, whiten the TIF noise and optimize the results of EKF, consequently, achieves a better performance than existing real time kinematic (RTK) solution. An experiment, which takes an active ionosphere condition into consideration, proves the feasibility of this system by comparing its records to that of a traditional RTK solution, practically, the system installed on the Donghai Bridge has survived a non-break running for five months. The analysis to the monitoring records shows the system achieves the designed accu- racy and reliability.     

Coupling Model of Vertical and Lateral Vehicle/Track Interactions

A new dynamic model of vehicle/track interaction is presented. The model considers the vehicle and the track as a whole system and couples the vertical interaction with the lateral interaction. The vehicle subsystem is modeled as a multi-body system with 37 degrees of freedom, which runs on the track with a constant velocity. The track substructure is modeled as a discretely supported system of elastic beams representing the rails, sleepers and ballasts. The normal contact forces between wheels and rails are described by Hertzian nonlinear elastic contact theory and the tangential wheel/ rail forces are decided by the creep theory. Numerical results are compared with those of conventional dynamic models of railway vehicles. Applications of the coupling model to the investigation of safety limits against derailment due to the track twist and the combined alignment and cross-level irregularities are reported at the end of the paper.     

铁路隧道接触网可更换预埋槽道新型锚杆型式研究及有限元分析

为解决铁路隧道内接触网预埋槽道承载力弱且不可更换等关键技术问题,在现有固定型式预埋槽道的基础上,设计了多种预埋锚杆结构型式的新型可更换预埋槽道。采用ABAQUS对预埋锚杆、锁紧螺杆、槽道、混凝土等主要构件的应力和变形进行分析,探究锚杆及混凝土的受力规律。研究表明： 1）螺纹的设计对预埋锚杆的轴拉效果有一定的提高,翼缘锚杆的支撑对于预埋锚杆抗拉拔和抗剪切性能有较大提升; 2）更多翼缘的设计使轴拉时的混凝土压应力显著减少,但略增大了混凝土的拉应力,对抗剪切性能提升有限; 3）相比变截面型式的预埋件性能提升不大且加工制作较为复杂,单翼缘带螺纹的设计更为合理,可对此进行进一步设计。     

客运专线路基模量测定仪与压路机械集成系统的研制

对客运专线路基模量测定仪与压路机集成系统进行了介绍。阐述了其工作原理和集成系统结构，并分析了试验检测结果，证明其对提高工程质量和施工效率有显著的效果。     

新机动车驾驶人考试制度浅析及场地改造方案设计

以沈阳市八棵树驾驶人考试中心为工程背景,对驾考制度中调整的科目进行分析,并依据设计原则及规定,进行相关科目考试场地改造的规划设计,对其他地区驾驶人考试场地的规划设计具有参考意义。