基于驾驶特性的超车模型研究

超车行驶作为驾驶人行车过程中重要的行为之一,与行驶安全性有着直接的联系。为建立符合驾驶人操作习惯的超车模型,本文通过实车试验采集不同驾驶人在高速公路的超车行驶数据,并以此采用多项式回归拟合建立基于驾驶人操作特性的超车模型,最后利用prescan软件对提出的超车模型进行了仿真分析,结果表明建立的超车模型能够真实地反映驾驶人超车过程中的操作习惯,为超车行为的研究提供了可靠的理论依据。     

汽车操纵性和稳定性的联合优化

在二自由度汽车操纵动力学模型和汽车开环系统操纵性、稳定性评价指标的基础上，提出了同时考虑汽车操纵性和稳定性的加权操纵稳定性评价指标，以及考虑各种车速重要性的加权均匀操纵稳定性评价指标。应用复合形法，对汽车操纵性和稳定性进行的联合优化实例表明，利用所提出的加权均匀操纵稳定性评价指标，可以有效地实现汽车操纵性和稳定性在所有车速范围内的优化。     

Fully nonlinear simulation for fluid/structure impact: A review

This paper presents a review of the work on fluid/structure impact based on inviscid and imcompressible liquid and irrotational flow. The focus is on the velocity potential theory together with boundary element method （BEM）. Fully nonlinear boundary conditions are imposed on the unknown free surface and the wetted surface of the moving body. The review includes （1） vertical and oblique water entry of a body at constant or a prescribed varying speed, as well as free fall motion, （2） liquid droplets or column impact as well as wave impact on a body, （3） similarity solution of an expanding body. It covers two dimensional （2D）, axisymmetric and three dimensional （3D） cases. Key techniques used in the numerical simulation are outlined, including mesh generation on the multivalued free surface, the stretched coordinate system for expanding domain, the auxiliary function method for decoupling the mutual dependence of the pressure and the body motion, and treatment for the jet or the thin liquid film developed during impact.     

新型深水多立柱 FDPSO 涡激运动研究进展

平台涡激运动易导致立管及系泊系统疲劳损伤,危害其安全、稳定性。平台由于具有较小的纵横比、显著的刚性特征及特有的系泊系统,其涡激运动显示出与立管等细长体涡激振动截然不同的运动特征。文中介绍了FDPSO常采用的特殊升沉补偿装置、多立柱绕流特性及多立柱海洋平台涡激运动的研究进展。鉴于深水多立柱FDPSO涡激运动及稳定性研究是非常复杂的流固耦合问题,文中给出了研究其涡激运动的基本思路和步骤,介绍新型多立柱FDPSO涡激运动的研究方法及现状,为其涡激运动抑制及抑制装置研制提供理论支撑。     

地面出入式盾构隧道稳定性控制措施有效性研究

文章以南京地面出入式盾构工程为背景,采用三维有限元模拟了地面出入式盾构隧道的整个施工过程,通过在模型中施加隧道内部压重与地表堆载,研究了两者对控制隧道上浮量、提高隧道稳定性的有效性。分析计算结果与现场监测数据表明:内部压重能够明显地提高隧道的稳定性,且效果比较明显;地表堆载也能在一定程度上减小隧道的上浮量,但其效果没有内部压重明显;施工中应结合现场实际条件,综合采用两者来实现最佳的稳定隧道效果。     

Engineering projects real-time supervision mechanism based on grid management

This paper proposes an innovative supervision method that can provide project supervisors with real-time supervision of engineering projects and contractor activity. To obtain real-time and comprehensive state of project, we use grid management to divide the project supervision grid in three levels： stage, objective, and milestone. Then, a detailed supervision mechanism is designed to help supervisors measure the project situation in real time. This mechanism checks that if the project objectives （such as schedule, cost, quality, and safety） in every supervision grid cell are under the healthy limits, any project deviation can be identified as soon as possible. A schedule objective is selected as an example to illustrate the method used to calculate the healthy limit.     

AgO的制备及影响因素分析

采用液相沉淀法制备AgO粉末,对其影响因素的机理和规律进行了分析,并利用XRD、SEM等测试手段对制备的AgO粉末进行了表征.研究结果表明,采用液相沉淀法制备AgO粉末的最佳条件为：m（K2S2O8）/m（AgNO3）=1.2,m（NaOH）/m（AgNO3）=2.5,反应温度60℃,反应时间为8h.制得的AgO含量为99.07％,粒度约为1～3μm.     

某型计程仪发送装置测试系统设计与实现

某型计程仪是舰艇中一个非常重要的航海设备,其发送装置负责把计程仪的速度和航程信号发送给全舰雷达、声纳、指控、导航等系统各用户。设计和研制该发送装置测试系统可以在内场中修时完成该型计程仪发送装置的调试和修理,解决该发送装置维修条件缺乏的难题。     

改性菜籽油的制备及其摩擦学性能研究

绿色润滑基础油的研究工作在国内外得到了越来越多的重视。以菜籽油为原料,进行酰胺化改性,通过碱值和氮含量的比较,挑选出两种改性菜籽油作为润滑基础油,和纯菜籽油以及加氢油5Cst在四球摩擦磨损试验机上进行摩擦学性能比较,发现改性后的菜籽油相对有较好的极压、抗磨和减摩性能。EDS对磨损钢球表面分析得出醇胺改性后的菜籽油由于含有活性氮元素,其在摩擦表面形成有机氮和无机氮组成的复杂膜,可以明显提高基础油的摩擦学性能。     

Parametric analysis of wheel wear in high-speed vehicles

In order to reduce the wheel profile wear of highspeed trains and extend the service life of wheels, a dynamic model for a high-speed vehicle was set up, in which the wheelset was regarded as flexible body, and the actual measured track irregularities and line conditions were considered. The wear depth of the wheel profile was calculated by the well-known Archard wear law. Through this model, the influence of the wheel profile, primary suspension stiffness, track gage, and rail cant on the wear of wheel profile were studied through multiple iterafive calculations. Numerical simulation results show that the type XP55 wheel profile has the smallest cumulative wear depth, and the type LM wheel profile has the largest wear depth. To reduce the wear of the wheel profile, the equivalent conicity of the wheel should not be too large or too small. On the other hand, a small primary vertical stiffness, a track gage around 1,435-1,438 mm, and a rail cant around 1：35-1：40 are beneficial for dynamic performance improvement and wheel wear alleviation.