Voith新技术:集离合器和缓速器于一体的新型液压制动系统VIAB

在2008第62届国际汽车展览会(IAA)商用汽车展览会上,VoithTurbo(福伊特驱动)公司展示了其最新开发的用于商用车的新型液压制动系统--VIAB.该系统将离合器和转矩转换器以及缓速器的功能集成到同一个系统中,并置于发动机和变速器之间(目前通常情况下缓速器位于齿轮箱外的变速器与传动轴之间).     

翻模技术在桥梁高墩施工中的应用

随着社会的快速发展和科学技术的进步,人们对于公路桥梁建设的质量提出了越来越高的要求和标准。公路桥梁作为我国重要的基础性工程,为人们的出行提供了极大的便利。翻模技术作为桥梁高墩施工中一个重要的组成部分,它的质量直接影响着桥梁高墩施工的整体质量,进而会对桥梁施工的质量造成影响。就翻模技术在桥梁高墩施工中的应用进行了探究。     

干线公路无控交叉口振动减速标线设计与舒适性评价

为了降低干线公路无控交叉口处驾驶员超速行驶产生的交通事故,在交叉口处进行振动减速标线设计,并探讨了振动减速标线的参数设计方法.采用改进加权加速度均方根与K值系数法相结合,建立振动频率、振动幅度和车速变化因子的综合舒适性评价模型.针对不同振动减速标线组数和车辆减速度,进行振动减速标线设计,分析不同减速效果下驾驶员的舒适性.     

基于CMOS图像传感器的视频采集系统设计

以OV7620为例，介绍了CMOS图像传感器的一般特征、内部结构及其使用特点，分析了0V7620的视频输出格式和工作方式，并在此基础上结合TI的C5402芯片和复杂可编程逻辑器件EPM7128设计了-视频图像采集系统，对系统的软硬件设计过程作了说明，对其可行性作了简要的分析，并在实际工程中得到应用．     

软弱围岩偏压隧道围岩压力计算公式推导与分析

通过对软弱围岩中偏压隧道围岩压力的公式进行推导,分析公式中所涉及参数之间的关系,得出这些参数的变化对侧压力系数和衬砌荷载强度的影响。结果表明:当两侧滑动面的摩擦角和计算摩擦角一定时,随着地面坡角的增加,侧压力系数呈现出增长趋势,而衬砌上的荷载强度呈现出降低趋势;当地面坡角和计算摩擦角一定时,随着两侧滑动面的摩擦角增大,侧压力系数表现出增长趋势而衬砌上的荷载强度出现降低趋势;当地面坡角和两侧滑动面的摩擦角一定时,随着计算摩擦角的增大,侧压力系数为降低趋势而衬砌上的荷载强度呈增长趋势。     

路基工程施工的质量监理

路基工程的施工监理，是公路工程施工监理的重要组成部分，是保证路基工程施工质量的关键，为此应搞好施工准备阶段监理，施工阶段监理和完工阶段监理。     

德尔菲法在水利枢纽工程景观桥方案比选中的应用

对于交通系统外的行业,设计人员对其行业特点、要求了解较少,要使设计方案能体现行业特性迅速得到其认可通常比较难。提出利用德尔菲法优选桥梁方案的新方法。以峡江水利枢纽坝顶景观桥为例,聘请15位水利系统的专家,经过两轮征询,在满足功能要求前提下,对桥梁设计方案的结构安全、施工难度、后期管护、工期、造价、景观效果等6项方案优选的权重进行了研究,通过定权求和得到方案的优劣排序。方案比选结果表明：优选出的方案符合业主需要,并兼顾了实际情况,节省了前期设计周期。     

城市超小净距暗挖隧道施工动态数值模拟分析

采用CRD工法及相关辅助工法对在冲积层中,洞间距仅为1 m,围岩软弱的城市浅埋双洞隧道进行暗挖施工,用数值模拟方法实现了这一复杂开挖施工过程.该方法主要运用有限差分程序,利用应力释放法及三维实体模型对隧道的开挖施工过程进行了三维动态模拟分析,总结了隧道拱顶、地表、地层沉降规律,研究了开挖施工中地层的塑性破坏区变化情况和中间岩柱的受力特点等,并将模拟数据与相关实测数据进行比较,认为此法合理、可行,可为以后的设计和施工提供参考.     

Degradation Reliability Analysis Based on TOPSIS Model Selection Method

It is necessary to determine the degradation path model of products at first when using the method based on degradation path model to evaluate the degradation reliability of products.At present,the degradation path model is mainly determined by scatter plots of degradation data.However,this method has strong subjectivity and is liable to cause the evaluation results to be inconsistent with the actual situation.In this paper,a degradation reliability analysis method based on TOPSIS(technique for order preference by similarity to an ideal solution)model selection is proposed,and its implementation process is given.The optimal degradation path model is selected according to the calculated proximity.With the help of TOPSIS method,various degradation path models can be selected and quantified,and the original degradation path method can be improved to avoid the risk of errors in product reliability evaluation caused by inaccurate subjective hypothesis,so as to ensure the objectivity and accuracy in the process of model determination.The validity and practicability of the proposed method are verified by the degradation analysis of the injector of a certain type of diesel engine.     

Energy Separation and Explicit Dynamic Analysis of Low Temperature Impact Toughness of Transmission Tower Material Q420B

To determine the physical significance of the impact toughness parameters and accurately characterize the low temperature impact toughness of transmission tower material Q420 B,the finite element model of Charpy impact test is established on the basis of experiment.The simulation and test results are verified,and the specimen fracture is analyzed by scanning electron microscope.The formation and growth mechanism of the crack are dynamically analyzed.On this basis,energy separation method is used to investigate the effect of low temperature on impact toughness.The results show that the simulation and test results are in good agreement,and the ductile-brittle transition temperature of Q420 B is about-50 ℃.The breaking process of the specimen is divided into the crack formation and propagation.When temperature drops from 20 to-60 ℃,the crack propagation energy decreases from 51.0 to 11.9 J,the crack formation energy reduces from 39.9 to 15.8 J,and the fracture time of the material drops from 1.8 to 0.6 ms.