基于Virtools的某型导弹虚拟维修视景仿真设计

使用建模工具3DSMAX2010建立了场景的三维模型和虚拟装备三维模型,运用Virtools编辑各种维修场景,构建出了与实际环境一致的虚拟维修环境。系统根据操作员的动作指令,实时显示人机交互过程,展示模型的状态变化,操作之后的场景响应过程,使得虚拟环境和实装操作一致,实现了某型导弹虚拟检测维修训练。该虚拟维修训练系统可以应用于相关部队的维修训练,达到节约训练经费,提高训练效果的目的。     

地铁明挖区间废水泵房破除改造方案研究

已投入运营的武汉地铁4号线明挖区间右线废水泵房侵入拟建5号线盾构区间限界,需对其进行破除改造。通过对1 m、3 m及5 m破除进尺长度时各施工工况进行数值模拟分析,获得不同破除进尺长度时各施工工况下明挖区间结构及土体变形情况。分析结果表明:采用5 m进尺长度的破除施工方案是可靠的、合理的;破除所引起的结构变形主要集中在4号线区间右线结构顶、底板,破除结构前应于紧邻破除区5.0 m范围内设置水平、垂直向临时钢管支撑。数值分析所得数据和结论不仅为破除改造时的支护体系设计提供依据,也可为类似工程提供有益的借鉴。     

圆柱体表面缺陷检测的ANSYS仿真

采用交变磁场测量的圆柱体表面缺陷的ANSYS仿真,以各向同性铝圆柱体为试件,采用柱坐标系及矩形激励线圈,电流流向为圆柱体轴向.将圆柱体体划分后再对各分体局部网格划分.划分较密的缺陷部分向周围划分较疏部分过渡时,采用四面体自由划分衔接.对带有表面周向缺陷的圆柱体网格划分后,产生的单元类型为四面体与六面体的混合.其仿真采用波前求解器.仿真路径为激励线圈沿缺陷长度方向、经过缺陷中心点进行周向移动.     

横泉水库帷幕灌浆试验点分析

横泉水库工程地质条件复杂,采用帷幕灌浆的方法对风化岩层进行处理以满足水库对防渗要求.风化岩层上为厚度16～30m的覆盖层,覆盖层由土层和砂卵石层组成.主要介绍了深覆盖层下风化基岩帷幕灌浆试验的钻孔、灌浆施工方法及其灌浆效果分析.为风化基岩帷幕灌浆积累了经验,可供同类大型工程帷幕灌浆时参考.     

An Improved On-line Contingency Screening for Power System Transient Stability Assessment

This paper presents a contingency screening method and a framework for its on-line implementation. The proposed method carries out contingency screening and on-line stability assessment with respect to first-swing transient stability. For that purpose, it utilizes the single machine equivalent method and aims at improving the prior developed contingency screening approaches. In order to determine vulnerability of the system with respect to a particular contingency, only one time-domain simulation needs to be performed. An early stop criteria is proposed so that in a majority of the cases the simulation can be terminated after a few hundred milliseconds of simulated system response. The method’s outcome is an assessment of the system’s stability and a classification of each considered contingency. The contingencies are categorized by exploiting parameters of an equivalent one machine infinite bus system. A novel island detection approach, appropriate for an on-line application since it utilizes efficient algorithms from graph theory and enables stability assessment of individual islands, is also introduced. The New England and New York system as well as the large-scale model of the Continental-European interconnected system are used to test the proposed method with respect to assessment accuracy and computation time.     

某超深矿山竖井修复及加固方案的论证分析

某水泥厂矿山竖井发生严重垮塌导致无法使用。通过综合分析对比,并基于二维有限元数值模拟,确定了钢模板+钢筋混凝土衬砌(内模法)+锚杆(土钉封堵法)+锰钢护筒(护筒跟进法)的修复及加固方案。该方案的成功实施验证了其可行性,可作为矿山竖井修复、加固工程中的成功案例。     

大型水轮发电机通风模拟试验台新型测控系统设计与实现

针对大型水轮发电机通风模拟试验要求,设计并提供了一种基于远程控制技术、虚拟仪器技术、PXI技术的先进的、功能完善的测控系统,并在文中论述了该测控系统的设计方案及其实现方法。该测控系统实现了大型水轮发电机通风模拟试验的自动控制与测量,试验结果表明,该系统具有测量与控制精度高、实时性、稳定性高以及抗干扰能力强等优点。     

Bearing behavior and failure mechanism of squeezed branch piles

The current practice for the design of squeezed branch piles is mainly based on the calculated bearing capacity of circular piles. Insufficient considerations of the load-transfer mechanism, branch effect and failure mechanism, as well as overreliance on pile load tests, have led to conservative designs and limited application. This study performs full-scale field load tests on instrumented squeezed branch piles and shows that the shaft force curves have obvious drop steps at the branch position, indicating that the branches can effectively share the pile top load. The effects of branch position, spacing, number and diameter on the pile bearing capacity are analyzed numerically. The numerical results indicate that the squeezed branch piles have two types of failure mechanisms, i.e. individual branch failure mechanism and cylindrical failure mechanism. Further research should focus on the development of the calculation method to determine the bearing capacities of squeezed branch piles considering these two failure mechanisms.     

子结构拟动力试验的CD-Wilson θ法研究

子结构拟动力试验中的组合数值积分方法具有显式数值积分方法无需迭代和隐式数值积分方法无条件稳定的优点。为解决CD-Newmark方法存在上限频率取值较大导致时间步长变小的问题,将显式的中心差分法和隐式的Wilson-θ法进行组合,形成CD-Wilson θ法。经计算和对Wilson-θ法做出一定修正后,得出该组合数值积分方法的稳定性和精度条件。通过Matlab软件编程,提出了CD-Wilson θ法稳定性的参数取值范围,并用算例做出对比验证。结果表明这种组合数值积分方法不仅稳定性和精度性好,而且比CD-Newmark法的时间步长范围更大。     

浅议小型水库防洪中的RCC护面技术

小型水库在社会发展中具有重要作用。如何做好防洪加固,是小型水库面临的主要问题之一。本文分析了小型水库面临的防洪问题,探讨了 RCC 护面技术在小型水库防洪中的应用,希望能对相关工作有所帮助。