基于十四面体模型的开孔泡沫材料弹性模量的有限元分析

利用十四面体模型描述开孔泡沫材料的胞体结构,并用有限元方法确定开孔泡沫材料的弹性模量。计算中使用相同尺寸的十四面体胞体模型,并考虑两种不同支柱截面（圆截面和Plateau截面）形状对弹性模量计算的影响。此外,通过数值方法研究开孔泡沫材料的弹性模量随模型尺寸的变化规律。同时,讨论边界条件处理对开孔泡沫材料弹性模量计算的影响。结果表明,支柱为Plateau截面形状的模型,其弹性模量明显高十具有圆截面支柱模型的结果。且两种模型的弹性模量均随模型尺度的增加而增加,最终趋于一个稳定值,并与Warren和Kraynik的理论预测较为一致。此外,边界条件对模型刚度的影响随着模型尺度的增加而逐渐减小。     

受压圆筒矩形大开孔的三维有限元分析与强度评定

本文针对卷染机蒸罐这样一种受压简体矩形大开孔进行了三维有限元分析,发现接管圆角过渡区有若干点的虚拟弹性应力值远大于材料在设计温度下的屈服限。本文依照ASME—Ⅷ——2及JB4732—95《钢制压力容器分析设计标准》的要求,针对受压圆筒——接管结构提出了一种强度评定方法。并对卷染机蒸罐进行了强度评定。     

V型缠绕垫片的力学分析及性能研究

对V型缠绕式垫片进行简化力学分析，并通过合理的设计、性能试验加以验证。     

V型压电换能器的有限元分析与实验

为实现对不同方向环境振动能量的收集,提出了一种新颖的V型压电换能器,对其进行了有限元仿真分析和实验测试.有限元分析表明,压电陶瓷片与金属弹性基片之间有一个最佳厚度比,为0.5,使得换能器发电能力最强.随着换能器两金属基片夹角的增大,其输出电压不断减小.实验测试显示,有限元分析与实验结果具有较好的一致性,且都在压电陶瓷片厚度为0.15 mm时,其输出开路电压最大,验证了有限元分析的可靠性,在输出功率测试中,V型压电换能器对外负载供能具有较好的优越性,且在峰值为0.3N的作用力下,输出功率达到22 μW.     

水平中开多级泵承压部件有限元分析及密封性能评估

基于有限元仿真平台,采用六面体与四面体组合网格离散三维几何模型,对某水平中开多级泵承压部件在充分考虑壳体中分面接触问题,管口载荷以及螺柱预紧力对结构影响的基础上,对泵本体在不同水压条件下进行有限元分析,然后又对-60℃和120℃极限工况下进行了仿真计算,并与常温工况进行了比较;此外还对泵本体进行了模态仿真和中开面的密封性能评估,获得了泵本体的固有频率及中开密封面的压力分布;为产品设计开发、优化结构提供了理论依据.     

关于某V型柴油机性能计算分析研究

针对某款新开发的V型柴油发动机,为确保设计之初就对性能进行模拟计算分析,利用AVL Boost一维性能软件对该机型进行模拟计算,通过建立计算模型对进气系统、增压器和气门升程规律进行模拟和预测,得出初步性能结论,为后续试验开发提供了宝贵的数据并指导性能优化方向。     

折弯机机架体的有限元法参数化建模及分析

以某机床厂的折弯机机架体为研究对象 ,使用大型通用化有限元软件ANSYS作为分析工具。利用APDL语言对其进行参数化建模 ,并进行了线性静态分析 ,得出了该部件的刚度及其强度值 ,为后续的优化提供依据     

多V型皮带轮旋压成形过程的有限元分析

基于动力显式有限元软件,以电磁离合器皮带轮为侧,开展了两个工序的旋压成形工艺的数值模拟,研究了旋压成形过程中材料变形情况,对成形件的应力应变分布进行了分析。模拟结果表明：采用旋压成形工艺,通过设置合理的进给量、芯模转速等参数,成形出的零件不仅形状和尺寸满足要求,而且芯模和旋轮所受载荷不大,旋轮最大载荷为540kN,芯模最大载荷为19kN。该研究对旋压带轮的非线性有限元分析和实际生产中设备的选择具有一定的参考和实用价值。     

一种V型切口应力强度因子的计算公式

基于奇异点附近的应力场,利用最小二乘法提出一种确定应力强度因子的数值方法,并获得了应力强度因子的计算公式,利用有限元软件ANSYS对90°V型切口应力强度因子进行了计算分析,结果表明该公式给出的结果可靠,精度高,便于工程运用。     

M型氧气压缩机气缸套有限元分析及参数化设计

气缸套是压缩机气缸的最重要的部件之一,其强度、刚度决定了压缩机的使用寿命。本文基于VS2005编程软件对Pro/E进行二次开发,设计出气缸套参数化设计系统,并导入到ANSYS Workbench中对气缸套进行了有限元模态分析。分析了气缸套的固有特性,为压缩机进一步优化设计和动态特性分析提供了理论依据。与常规设计方法相比较,参数化设计与有限元分析方法的结合提高气缸套设计效率2倍以上,具有广阔的应用前景。     

CATIA V5在引擎盖逆向造型中的应用

论述了逆向工程的概念以及车身外表面的逆向造型过程,介绍了CATIA V5逆向工程相关的功能,以汽车引擎盖为例阐述了CATIA V5在车身逆向造型中的具体应用方法和技巧,总结了逆向造型中保证曲面质量的几个重要环节.     

A system for measuring mechanical stresses in a vessel hull

Sensors of the stressed state of hulls and systems that gather and process information from those sensors play a special role in the monitoring of the strength of vessel structures. Magnetoelastic transducers are the type of sensors that are most suitable for this purpose. This study is devoted to the development of a system for monitoring the stressed state of a vessel hull that meets the modern requirements of norms and rules regarding the monitoring of the stressed state of a vessel hull. The proposed monitoring system incorporates a unit for digital processing of signals and mandatory recording of the measurement process. The system was developed taking into account marine conditions; issues of technical maintenance and the cost of the proposed project were also considered. Options for the use of the mathematical regression method in monitoring of stresses in hull structures of vessels are analyzed. Approaches to the development of the system for monitoring stresses in hulls are outlined.     

船用液压缸承载能力的有限元分析

1前言液压缸是船用液压系统中常用的一种执行元件,是把液体的压力能转变为机械能的装置,主要用于实现机构的直线往复运动。船用液压缸工作的可靠性直接关系到船机设备的正常运行,为了给液压缸的设计和维修提供可靠的数据,本文运用有限元方法对某船用舵机液压缸承受40 MPa的载荷的受力情况进行了计算,并对计算结果进行了应力和变形分析。     

CATIA V5在汽车数字化工程中的应用

本文从汽车整个开发周期的角度阐述了CATIA V5在汽车数字化工程中的应用,包括数字样机、形状虚拟样机、虚拟装配等,提出了一个基于CATIA V5的汽车数字化工程开发流程。     

New device for analysis of metal particles in oil

A portable graphite furnace atomic absorption (AA) spectrometer, developed under a contract for this laboratory, has been evaluated using powdered metal particles suspended in oil. The portable wear metal analyzer (PWMA) was designed to support the deployed aircraft requirement for spectrometric oil analysis. The PWMA is a microprocessor-controlled automatic sequential multielement AA spectrometer packaged in two cases having a total weight of 49 kg. The PWMA will analyze for nine elements (nickel, iron, copper, chromium, silver, magnesium, silicon, titanium and aluminum) at a rate of 4 min per sample. The graphite tube and modified sample introduction system increase the detection of particles in oil when compared with the currently used techniques of flame AA or spark atomic emission spectroscopy and represent the major reason for this work — the qualification and calibration of the PWMA with known “wear metal” samples in turbine engine oil. Five (nickel, iron, copper, chromium and silver) of the nine elements analyzed by the PWMA are reported here owing to space limitations. These five elements represent the minimum and maximum concentration ranges of all nine elements. The PWMA shows good-to-excellent response for particles in the size ranges 0–5 and 5–10 μm and fair response to particles of 10–20 and 20–30 μm. All trends in the statistical variations are easily explained by system considerations. Correction factors to the calibration curves are necessary to correlate the analytical capability of the PWMA to the performance of existing spectrometric oil analysis instruments.     

Analysis of new method for vertical load measurement in the barycenter of the rail web by using FEM

Continuous method for measuring the forces between the wheel and rail is very important to monitor track loads. One of the usual methods is installing a strain gauge on the rail surface. Thus, strain gauge exposed to aggressive environment that makes it difficult for system to measure exclusively vertical force component and has complex installation operation. In this paper, strain measurement to assess the vertical load on cross section barycentric of rail and the lateral surface of rail web are studied. For this purpose, finite-element analysis was performed and the forces that exchange between wheel and rail in contact location were replaced with the moving loads that were applied to the railhead directly. Size of the effective contact patch was obtained from Hertz contact theory and patch switching time was considered short enough to reach an approximate continuous moving load. The results demonstrate the magnitude of strain in vertical direction is approximately same for the cross section barycentric and lateral surface of the rail web. However, the great advantage of measurement in the cross section barycentric of rail better distinguishes longitudinal and lateral strains from the vertical and also lateral load on a rail has less effect on vertical load measurement.     

润滑油分析实验室废油的绿色环保处理

润滑油分析实验室在分析实验完成以后,总会有废油产生。这些废油由于很难在自然环境中自身消解,因此不能直接倾倒到环境中,而将废油作为燃料燃烧使用,虽然可以大大降低环境污染,但从经济角度来看,将造成很大的资源浪费。本文介绍了一种废润滑油再生技术。利用该技术可将废油再生使用,实现了润滑油分析实验室废油的绿色环保处理。     

A design procedure based on limit analysis for a pad reinforced nozzle in a spherical pressure vessel

A limit analysis of a pad reinforced flush nozzle in a spherical pressure vessel has been published previously. A procedure for the design of a pad reinforced nozzle is proposed using the analysis and based on equating the limit pressure to the vessel test pressure. Design charts are presented for the case where the length of the reinforcing pad is that required to achieve the maximum limit pressure for a given set of dimensional parameters and also for the case where the length of the reinforcing pad is the minimum specified in present design codes. In all cases the amount of pad reinforcement required is greater than that for integral reinforcement using the same design principles.     

航空螺旋桨载荷测量遥测盘结构可靠性分析

为测量试飞中螺旋桨载荷大小,实现旋转桨叶载荷信号的实时传输,自研了一套载荷测量遥测系统。为保证螺旋桨载荷测量遥测系统装机试飞的安全性,对所设计遥测盘进行了强度计算、振动分析和旋转试验,结果表明所设计遥测盘结构与螺旋桨不会发生结构共振,且强度满足使用要求,可保证装机试飞安全。     

进口压缩机曲轴漏油故障分析与处理

针对进口CNG压缩机运行过程中出现的曲轴漏油故障进行研究分析，结合现场实际，找出一条行之有效且适用于该机型解决的办法。