轮胎非稳态转向特性非线性仿真模型

本文以轮与路面之间的滑移速度为出发点，在稳态指数统一模型的基础上，建立了轮胎非稳态转向特性非线性仿真模型。在实验研究中，发现了动态过程回正力臂和附加的回正力矩的滞后特性。仿真和试验结果对比表明，该模型足以反映轮胎非线性转向特性，可用于前轮及汽车操纵动力学仿真方面的研究。     

Ride Quality and Dynamics of Rail Vehicle Models for Microcomputers

This paper describes mathematical and computer models for ride quality and dynamics of rail vehicles developed for running on personal computers. The purpose of the computer simulations is for prediction of ride quality in order to study the dynamic stability of the system and the effect of track quality and irregularities on ride quality.

In deriving the equations of motion for dynamic stability, the tangential forces acting on the contact areas between the wheels and rails are of fundamental importance in railway vehicles dynamics and are included in the analysis [1]. These forces are due to the creep phenomenon between the wheel and the rail on which it is rolling. Track irregularities are defined in terms of four components consisting of gauge, cross level, alignment and vertical surface profile [2]. Relation of allowable track irregularities versus speed is given by the FRA Track Safety Standards. Analytical representation of track irregularities should include both PSD (Power Spectral Density) for CWR (Continuous Welded Rail) as well as discrete inputs from track joints.

In this paper, the rail vehicle suspension analysis and dynamics mathematical and computer models are described. The computer models are written in Fortran 77 and designed to run on personal computer. The paper also discusses programming considerations that must be taken into account when programming for microcomputers under DOS (IBM's Disk Operating System) and MS or RM Fortran Compilers. Most of the considerations are however, valid in general with respect to engineering software development and programming for microcomputers.

Computer graphics is a powerful tool for visualization of the resulting solutions such as the display of the characteristic roots for the eigenvalues solution on a root locus plot and representation of acceleration levels versus the “Reduced Comfort Boundary” limits defined by the International Standards Organization” (ISO 2631-1985). In this paper some examples of these resulting outputs are presented and their significance discussed.     

预应力砼新技术探索

在总结已有预应力砼技术优缺点的基础上, 提出了预弯双预应力复合梁、预弯预应力钢筋砼、预弯无粘结预应力砼、横张预应力砼技术的构思． 其中, 横张预应力砼技术集良好的使用性、用材的经济性和施工的简易性于一体, 具有很好的技术经济效益和推广应用前景．     

2005中国国际集装箱多式联运高级研讨会新闻通报2005年7月18号向支持媒体《集装箱化》提供并发布

经过紧张的筹备,中国国际集装箱多式联运研讨会（以下简称“研讨会”）将于2005年9月8-9日在中国北京京都信苑饭店召开。     

用于压力容器缺陷评定的设计曲线方法研究

本文在弹塑性断裂力学分析的基础上,提出了一种新的缺陷安全评定方法一如方法。 文中给出了妈设计曲线及其简化公式,并研究了现行压力容器缺陷评定规范设计曲 线方法用于幕硬强化材料的安全性问题,为进一步修订我国CvDA一84规范提供了 一条合理途径。      

损伤失效分析的数值原理及有限元列式

结构构件在外荷载的作用下,其材料逐渐衰变,表现出损伤演化进而最后失效的行 为,描述这一行为的损伤本构关系非常复杂并且有高度的非线性;本文基于连续损伤 力学(。ntinuuln压甘以seMechan油),提出用于结构损伤失效分析的数值原理,包括损 伤模型、失效准则、结构分析变分原理及相应的有限元列式;涉及到具有损伤翔合的 弹塑性问题及蠕变问题.      

损伤局部性方法研究进展

本文综述了应用力学研究所的教师、博士后人员和研究生们将损伤局部性方法 (LDA)用于娇变损伤和低周疲劳损伤分析以及细观损伤测量中的研究成果。展望了 损伤局部性方法进一步发展的前景。      

用于两种模型的综合推理方法

本文论述了将适于诊断型专家系统使用的最小集合覆盖模型推理方法用于分类模型的原理,并 对最小集合覆盖模型进行了理论完善和算法实现。模型所需的数据利用分类摸型中的产生式规 则产生。最后,通过两个现象子集间的贴近度计算求得结论的可信度。      

路动车组车辆表面清洗剂的研发

提出了铁路动车组车辆表面清洗剂研发的技术要求,介绍了清洗剂的化学适宜性.根据清洗剂的使用要求,提出了表面活性剂的选择方案,要求其具有黏度适中、易过水、无残留等特性.介绍了车辆表面清洗剂GD-21型系列产品的环保性能.     

Winkler弹性地基上预应力锚索地梁内力的计算方法

介绍用Winkler弹性地基梁计算预应力锚索地梁的内力 ,并给出主要计算流程。结合京珠高速公路某工点工程实例 ,将Winkler弹性地基梁和连续梁方法的计算结果与工程实测进行比较 ,指出在预应力锚索地梁正常工作状态下 ,采用Winkler弹性地基梁方法所得结果与真实情况更为吻合