军口科研设备招标采购的博弈与招标模式研究

随着招标在外军采办和我国各行各业的广泛开展,针对军口863项目科研设备的特点,分析了实施集中招标采购的必要性;并根据在招标过程中的博弈,建立了招标采购过程的不完全静态博弈模型,提出了实施公开招标的两阶段招标模式。实践证明,军口863项目科研设备实施集中招标采购可以避免设备的重复购置,减少项目资金的浪费,实现资源的优化配置。     

混凝土施工裂缝的控制

在道路施工中混凝土经常会出现遇度裂缝,影响到结构的整体性和耐久性。在路面的使用过程中,温度变化对结构的应力状态具有显著影响。在大体积混凝土施工中,对温度应力及温度控制具有重要意义。从分析混凝土裂缝的产生原因入手,对温度应力的形成过程进行论述,从而提出控制混凝土裂缝的措施。     

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首先选用较多的交通参数,设计提出了基于聚类方法的细粒度交通模式划分算法,将交通模式划分为较多的类别。结合实际数据,进行了实验,在四个路段参数的基础上,划分得到了十类交通模式。这其中都用到了模糊集合划分和定性推理。使用状态核确定一系列模式,随后系统状态被划分成若干个模式。提出了模式转移方程来描述在定性推理基础之上的状态转移,并从模式转移的角度进一步研究了系统的稳定性。一个城市交通系统的应用实例显示了本文提出方法的有效性,可以看出细粒度交通模式划分要比粗粒度有更多的优势,同时得出了聚类算法在细粒度交通模式划分中的劣势。     

双护盾TBM分体始发技术研究与在青岛地铁1号线的实施

为保证在不具备整体始发空间的条件下双护盾TBM分体始发顺利实施,以青岛地铁1号线海泊桥站为例,针对城市地铁隧道施工始发场地有限的客观条件,以实现施工功能为导向,通过配套设备的优化布置并最大限度地利用双护盾TBM自身配置实现有限场地内最经济的TBM分体始发,并对分体始发的基本方案进行探讨。经研究分析可知： 1）分体始发时双护盾TBM需具备的基本配套系统为高（低）压供电系统及控制系统、冷却水系统、液压系统、润滑系统、脂密封系统、压缩空气系统、豆砾石回填系统、注浆系统、导向系统及除尘系统; 2）通过管线、线缆的延伸,双护盾TBM可在主机与后配套之间或主机与部分后配套之间任何位置断开。     

Sliding window method for vehicles moving on a long track

The rail is modelled as a simply supported beam in the vehicle–track coupled dynamics. The beam is formulated by a partial differential equation that is transformed into an ordinary differential equation by the method of mode superposition for numerical calculation. However, the size of the matrix that is formed by the mode-superposition method increases significantly with track length, which limits the calculation efficiency. Some methods have been developed to solve this calculation issue, but they diminish the merits of the vehicle–track coupled dynamics, which would systematically investigate the dynamics of a vehicle and a track from the entire vehicle–track system. A new method is developed to resolve this contradiction. First, a theory based on a sliding window is established to improve the computational stability with respect to the length and the window-movement ratio. Then, two methods, namely finite element method analysis and an analytical solution, are used to verify the accuracy of the new method, which is highly efficient when used in a vertical half-vehicle–track coupled model to calculate the vehicle response when the vehicle moves on a long track. The results of the vehicle response calculated with and without the sliding window show good consistency.     

Measurements of car-body lateral vibration induced by high-speed trains negotiating complex terrain sections under strong wind conditions

Assessment of the vibration of high-speed trains negotiating complex sections of terrain under strong wind conditions is very important for research into the operation safety and comfort of passengers on high-speed trains. To assess the vibration of high-speed trains negotiating complex sections of terrain under strong wind conditions, we performed a field measurement when the train passes through typical sections of complex terrain along the Lanzhou–Xinjiang high-speed railway in China. We selected the lateral vibration conditions, including the roll angle and lateral displacement of car-body gravity centre through two typical representative sections (embankment–tunnel–embankment and embankment–rectangular transition–cutting) for analysis. The results show that the severe car-swaying phenomenon occurs when the high-speed train moves through the test section, and the car-body lateral vibration characteristic is related significantly to the state of the terrain and topography along the railway. The main causes for this car-swaying phenomenon may be the transitions between different windproof structures, and the greater the scale of the transition region between different windproof structures or landform changes, the more obvious the car-swaying phenomenon becomes. The lateral vibration of the car-body is relatively steady when the train is running through terrain with minor changes in topography, such as the windbreak installed on the bridge and embankment, but the tail car sways more violently than the head car. When the vehicle runs from the windbreak installed on the embankment into the tunnel (or in the opposite direction), the tail car sways more intensely than the head car, and the head car runs relatively stable in the tunnel.     

基于有限元的活塞组摩擦产热计算分析

基于有限元方法建立了活塞组摩擦产热计算模型,通过发动机工作过程的计算得到了活塞组摩擦产热计算所需的运动学和动力学边界。以某12缸增压柴油机为研究对象,计算得到了标定工况下其活塞组瞬时摩擦力及瞬时摩擦产热功率随曲轴转角的变化,活塞组平均摩擦产热总功率及其在活塞环、活塞裙部、气缸套的分配,以及活塞组摩擦产热所导致的活塞组、气缸套温升情况,计算分析了转速和负荷对活塞组摩擦产热的影响。     

A stochastic analysis of highway capacity: Empirical evidence and implications

This paper presents a stochastic characterization of highway capacity and explores its implications on ramp metering control at the corridor level. The stochastic variation of highway capacity is captured through a Space–Time Autoregressive Integrated Moving Average (STARIMA) model. It is identified following a Seasonal STARIMA model (0, 0, 2₃) × (0, 1, 0)₂, which indicates that the capacities of adjacent locations are spatially–temporally correlated. Hourly capacity patterns further verify the stochastic nature of highway capacity. The goal of this paper is to study (1) how to take advantage of the extra information, such as capacity variation, and (2) what benefits can be gained from stochastic capacity modeling. The implication of stochastic capacity is investigated through a ramp metering case study. A mean–standard deviation formulation of capacity is proposed to achieve the trade-off between traffic operation efficiency and robustness. Following that, a modified stochastic capacity-constraint ZONE ramp metering scheme embedded cell transmission model algorithm is introduced. The numerical experiment suggests that considering capacity variation information would alleviate the spillback effect and improve throughput. Monte Carlo simulation further supports this argument. This study helps verify and characterize the stochastic nature of capacity, validates the benefits of using capacity variation information, and thus enhances the necessity of implementing stochastic capacity in traffic operation.     

载货车悬置系统优化分析及改进

针对公司某款中型载货车发动机悬置隔振效果差的问题,提出了相对应的解决方案。根据现有车辆实验测定的振动数据和现有软垫的刚度参数,优化悬置系统的参数,应用ADAMS软件的分析优化,并通过振动试验的测定,最终达到优化悬置隔振的目标。为以后的载货车的悬置优化分析计算提供参考依据。     

基于Digatron电池测试系统的锂电池温度寿命试验技术研究

本文主要论述了利用目前国际主流的Digatron电池测试分析系统,选取温度作为表征锂电池组寿命特性的参数,设计了电池组性能试验,通过实验数据分析得到了锂电池组寿命特性趋势,对于改善车辆电池控制管理策略具有指导意义。