轮胎——路面接触压力问题研究

轮胎和路面接触压力问题主要涉及轮胎、路面以及它们之间相互作用的接触面等三方面问题。在查阅大量资料的基础上,综述了该领域目前国内外的研究现状、研究手段及方法,叙述了影响轮胎一路面接触面积大小的因素,同时提出作者对该问题的一些看法。     

铁路钻探卡钻事故分析

卡钻是钻探中的一种事故,常易造成较大损失.文章从岩层、钻井液、钻探设备、施工因素方面分析了卡钻原因,提出了预防措施,并结合向莆铁路钻探中的卡钻事故进行了分析,总结了一些有意义的结论.     

Sensitivity analysis and dynamic modification of modal parameter in mechanical transmission system

Sensitivity analysis is one of the effective methods in the dynamic modification. The sensitivity of the modal parameters such as the natural frequencies and mode shapes in undamped free vibration of mechanical transmission system is analyzed in this paper. In particular,the sensitivities of the modal parameters to physical parameters of shaft system such as the inertia and stiffness are given. A calculation formula for dynamic modification is presented based on the analysis of modal parameter. With a mechanical transmission system as an example, the sensitivities of natural frequencies and modes shape are calculated and analyzed. Furthermore, the dynamic modification is also carried out and a good result is obtained.     

永连公路k22处整体滑坡带病害整治

对永连公路其滑坡病害的机理进行分析,提出了病害的整治方案及方法。     

Ⅰ—Ⅱ混合型裂纹相变增韧分析

采用压力敏感准则和权函数法相变增韧陶瓷Ⅰ－Ⅱ混合型裂纹的增韧效应进行了理论预测,分别给出了静止裂纹和定常扩展裂纹相变塑性屏蔽的理论表达式。结果表明：相变对静止裂纹有负屏蔽效应,并随KⅡ／KⅠ的比值增大而增大;对定常扩展裂纹的增韧结果除与材料弹性模量、相变尾区高度和相变体积分数和有关外,还随KⅡ／KⅠ的比值增大而减小。     

回忆上海造船学会一二事

值此上海造船学会成立50周年之际,忆学会工作一二事,以表庆贺!     

Calculation of strain amplification matrix for strain invariant failure theory based on representative volume element models with periodical boundary condition

Strain invariant failure theory (SIFT) is a micro-mechanics-based failure theory for multi-scale failure analysis of composite materials originally proposed by Gosse and Christensen. In this paper, the approach for obtaining strain amplification matrix which is a key step for the execution of SIFT is improved by adopting representative volume element (RVE) finite element models considering periodical boundary condition, based on which more actual deformation mode is reflected. The deformation modes and strain data at the characteristic points of the centroid cell of multi-cell RVE model are analyzed and taken as a reference. It can be concluded that more reasonable deformation mode and relationship between the micro-mechanical and macro-mechanical strain states are obtained by employing the new model. Finally, numerical examples are provided to illustrate the determination of strain amplification factors within the RVEs considering periodical boundary condition at the characteristic points.     

电控空气悬架载荷平衡系统仿真

结合当代最新设计理念,利用MATLAB和ADAMS/Car软件的联合仿真,设计了电控空气悬架载荷平衡系统,并对整体系统进行了几个工况的模拟仿真。结果表明:所设计的空气悬架载荷平衡系统性能良好;联合MATLAB和ADAMS软件的长处来设计系统,能够使产品开发过程加快,同时产品开发成本也相应下降。     

大型体育赛事开闭幕式交通组织策划

大型体育赛事开闭幕式的人流、车流高度集中,对服务水平保障要求严格,媒体关注度较高.基于多项大型体育赛事开闭幕式交通组织方案编制和实施过程的思考,探讨开闭幕式交通需求的特点与挑战、交通组织策略、方案评估方法和指挥体系.指出开闭幕式交通组织策划需根据仪式流程,安保政策,各客户群体起讫点、出行时间和服务模式等,采用交通模型和...     

城市轨道交通与快速公交换乘时间衔接分析

在分析城市轨道交通与快速公交特点的基础上,以缩短出站乘客换乘时间为目的,重点研究利用快速公交疏散城市重点区域轨道交通站点产生的大量出站客流的协调条件。通过对城市轨道交通出站换乘时间的详细分析,将出站乘客换乘时间细分为四部分,建立乘客换乘总等待时间最短宏观模型,并分析造成乘客候车时间长的原因;运用时空图对两者换乘过程、换乘状态进行描述,探讨总结两者协调调度的条件。最后运用实例对该方法进行验证。