刚体动力学初值问题的拟变分原理及其应用

随着科学技术的发展,对刚体动力学提出新的要求.应用变积方法,建立了刚体动力学初值问题的拟变分原理.推导出刚体动力学初值问题的拟变分原理的拟驻值条件.建立了刚体动力学初值问题的广义拟变分原理,说明了应用广义拟变分原理求得问题的解析解和数值解的途径.借助算例说明了应用变分方法来研究刚体动力学初值问题的优越性.     

SMA-5应力吸收层在旧水泥路面加铺改造中的应用研究

为减少和延缓旧水泥板沥青加铺层反射裂缝的产生,在分析研究各种夹层材料应用效果和SMA-5作为应力吸收层性能要求的基础上,设计了SMA-5应力吸收层的配合比,采用搓揉成型的方法改进了马歇尔试件,并对SMA-5沥青混合料的各项路用性能进行了试验研究,且成功的铺筑了试验路.结果表明:SMA-5沥青混合料可以作为夹层材料,并起到了很好的应力吸收效果.此项研究成果对于旧水泥混凝土路面加铺改造具有重要的工程实用价值,SMA-5应力吸收层具有广阔的应用前景.     

差动放大电路共模干扰抑制能力的研究

电磁流量计输出的流速信号非常微弱,且常叠加共模干扰,经信号调理电路放大后,会导致信噪比很低,甚至淹没有用信号．针对这问题提出了利用前置放大电路有效抑制共模干扰,对其进行定性、定量分析,给出实际可行的提高差动放大电路输入阻抗的设计,并进行分析、推导和对比计算,证明其可以很大限度抑制共模干扰,提高测量准确度．     

基于无线通信方式的TV二次压降现场测试方法

针对传统的TV二次压降现场测试方法存在的问题,提出基于无线通信技术的检测方法。以提高工作效率,降低安全风险。     

基于ANSYS的车路系统力学分析

车辆荷载对路面的作用是导致路面病害的主要原因.以某道路改建工程为依托,通过大量的室内外实验,把实验的数据借助ANSYS力学分析软件进行路表弯沉、应力等静力学分析,得到最大值出现位置和应力变化趋势.考虑到路面上车辆行驶的运动特点,对车路系统进行了动力学分析,得到位移最大值及应力随时间的变化规律,为道路病害的预防提供了理论依据.     

铸造铝合金轮毂T6热处理工艺的优化研究

研究了固溶时间、淬火停留时间及涂装烘烤工艺对A356合金铸造轮毂性能的影响规律并优化了T6热处理工艺，将淬火停留时间缩短到2h。研究表明：未涂装时优化工艺使合金抗拉强度达到240MPa，屈服强度达到181MPa。伸长率达到8％；涂装后抗拉强度达到262MPa，屈服强度达到179MPa，伸长率达到9％，接近并达到目前国内T6工艺的强度性能，超过了国内轮毂行业的强度性能标准，具有一定的生产实际意义。     

坯料外形对镁合金矩形盒拉深成形的影响

用商业有限元软件模拟了在同一套模具和成形条件下不同毛坯外形的镁合金矩形盒拉深成形过程．依据数值模拟结果，分析了不同坯料外形对镁合金矩形盒拉深成形的影响。结果表明：使用矩形圆角坯料比其他坯料的成形性能好。     

A global cutter positioning method for multi-axis machining of sculptured surfaces

Traditional cutter positioning methods have defects of global errors and incomplete optimization. Because of using local differential geometry and focusing on the cutting contact point, these defects cannot be avoided and will deteriorate accuracy in precision machining. The authors presented the conception of actual cutting edge of a toroidal mill which was extended from cutting contact point, and pointed out its importance in programming. Instantaneous cutter position error (ICPE) was also investigated. A new global method based on the ICPE curve was presented. Taking the relationship between surface and cutter into consideration thoroughly, this global method shows many advantages which have been verified by simulation and cutting tests.     

Research on graphite powders used for HTR-PM fuel elements

Different batches of natural graphite powders and electrographite powders were characterized by impurity, degree of graphitization, particle size distribution, specific surface area, and shape characteristics. The graphite balls consist of proper mix-ratio of natural graphite, electrographite and phenolic resin were manufactured and characterized by thermal conductivity, anisotropy of thermal expansion, crush strength, and drop strength. Results show that some types of graphite powders possess very high purity, degree of graphitization, and sound size distribution and apparent density, which can serve for matrix graphite of HTR-PM. The graphite balls manufactured with reasonable mix-ratio of graphite powders and process method show very good properties. It is indicated that the properties of graphite balls can meet the design criterion of HTR-PM. We can provide a powerful candidate material for the future manufacture of HTR-PM fuel elements.     

三义寨引黄灌区多功能河道清淤船的研制

近年来,受黄河来水量减小及小浪底水库蓄水调沙作用的影响,三义寨渠首闸引水流量较小,导致引渠淤积、渠底抬高,造成灌区引水困难.为此,三义寨闸管处研发了多功能河道清淤船,该船由行走系统、起重架系统和吸沙排沙系统三部分构成,船体吃水深度为0.6m,吸沙能力为0.75 ～ 1.0 t/min,清淤深度为1.5～1.6m.生产实践表明,它可满足三义寨引渠的清淤作业,与租用机械清淤对比,多功能清淤船的经济效益显著.