制冷装置蒸发器异型管板的有限元分析

基于制冷装置蒸发器异型管板无设计标准可依的现状,对该系列蒸发器管板的稳态温度场和热应力场进行三维有限元分析。运用Visual Basic和ANSYS二次开发工具APDL,实现了管板的参数化有限元分析。并对该系列不同布管方式的3种管板进行了分析比较。分析结果表明,该系列蒸发器管板布管形式在一定范围内对管板强度影响不大,现有管板工程设计偏于保守,可进一步进行优化设计。     

带降液管蒸发器管板的强度分析

提出了带降液管蒸发器管板的应力分析力学模型,介绍了有限元应用于应力求解的方法,并通过对ＴＢＺ１４００、ＴＢＺ１２００蒸发器管板的实验应力测试,验证有限元法的有效性     

轻工用蒸发器管板的设计计算

轻工用蒸发器管板有其结构和使用条件的特殊性,不宜采用ＧＢ１５１进行管板设计计算,本文分析了影响轻工用蒸发器管板强度的各种参数,利用有限元法求解多组蒸发器管板最大应力,并用最小二乘法推导出管板计算公式。     

换热器管板有限元分析模型研究

建立3种换热器管板有限元分析的简化模型:当量实心板与杆单元模型(模型A);实体管板与杆单元模型(模型B);实体管板与壳单元模型(模型C),通过典型算例,将3种简化模型的计算结果与全实体模型(模型D)进行对比分析。结果表明,模型C管板的应力强度、轴向位移及管束轴向力均与实体模型D较为接近,且得到保守结果,计算精度及效率优势较为明显。     

轻工行业蒸发器管板设计计算的标准及其软件编制

介绍轻工行业蒸发器管板设计计算标准QB／T2068及其使用的问题,采用Visual Basic编制相应计算程序。     

管壳式热交换器管板设计规范分析

本文根据管壳式热交换器管板设计规程所依据的理论基础,分析了TEMA、GB151、CODAP、ASME草案、AD等管板设计规范,同时对它们的一些异同点做了比较,并由此展望管板设计规范的发展。     

绞车轮毂有限元分析及优化设计

文章以JTP-1.6型绞车为例,针对该绞车成本过高这一问题,对绞车轮毂进行分析,通过ANSYS有限元分析软件建立了矿井绞车轮毂的有限元模型,分析轮毂在最大受力情况下的应力集中情况以及变形位移情况,通过这些计算分析,为轮毂的优化设计提供了一些具有参考价值的建议,为现场安全生产提供了有力的技术依据。     

谈谈管板孔桥宽度确定

管壳式换热器是工业生产中用于热量传递的设备．广泛用于石油、化工、轻工等诸多行业中。尤其在我们真空制盐、制硝是不可缺少的关键设备。而在管壳式换热器中，管板又是其重要的组成部分和受压元件之一。设计中为厂保证管板的整体质量，管板孔桥宽度B及最小宽度民un这一技术数据设计者必须明确提出，并在管板施工图上标明，作为管板制造加工和检验的依据。本文就管板孔桥宽度及最小宽度，特别是当所设计孔间距与GB151－－ng钢制管壳式换热器》中的标准值有出人时的确定，介绍一种计算方法，供设计时参考。通常，管壳式换热器的设计，在换…     

Fuzzy finite element analysis of heat conduction problems with uncertain parameters

In this article we have used four different global optimisation algorithms for interval finite element analysis of (non)linear heat conduction problems: (i) sequential quadratic programming (SQP), (ii) a scatter search method (SSm), (iii) the vertex algorithm, and (iv) the response surface method (RSM). Their performance was compared based on a thermal sterilisation problem and a food freezing problem. The vertex method proved to be by far the fastest method but is only effective if the solution is a monotonic function of the uncertain parameters. The RSM was also fast albeit much less than the vertex method. Both SQP and SSm were considerably slower than the former methods; SQP did not converge to the real solution in the food freezing test problem. The interval finite element method was used as a building block for a fuzzy finite element analysis based on the α-cuts method. The RSM fuzzy finite element method was identified as the fastest algorithm among all the tested methods. It was shown that uncertain parameters may cause large uncertainties in the process variables. The algorithms can be used to obtain more realistic modelling of food processes that often have significant uncertainty in the model parameters.     

热轧非织造材料力学性能有限元分析*

利用同轴反射光显微镜拍摄热轧非织造材料的多层图像,结合多聚焦图像融合技术,得到材料的清晰图像和纤维位置信息;再通过python编程构建热轧非织造材料几何结构有限元模型,运用ABAQUS程序实现材料力学拉伸性能模拟,获得不同模型参数条件下应力-应变曲线。对比不同参数条件下有限元模型所得的应力-应变曲线发现：材料中热黏合点可以视为弹性体;在应变为0．38时纤维性能对整体材料应力的影响为30％,而热轧辊温度、生产速度和纤网面密度等因素对整体材料的应力影响为70％。     

应用有限元模型分析木制品榫结合的力学性能

介绍了使用有限元模型分析三种木制品榫结合力学性能的方法和过程,并对三种木制品榫结合的计算结果进行了讨论。模拟和试验结果表明有限元模型分析方法为木制品榫结合计算机辅助结构设计和分析提供了更科学的依据。     

A finite element model for the analysis of roll burnishing

This study presents the analysis of roll burnishing using the finite element method. The distribution of the residual stresses as a function of the load applied is modelled, the new frequencies and the critical speed of the plate are calculated, the upper limit of tensioning and the influence of the curvature of the plate are discussed. Then, a static analysis is done which explains the measurement method generally used in the industries.     

玄武岩纤维增强复合材料的制备及有限元分析

选取玄武岩纤维作为增强材料,聚丙烯(PP)为基体材料,采用模压工艺制备复合材料.采用单因子试验法研究了温度、压力及保压时间对玄武岩/PP复合材料力学性能的影响,结果表明:不同工艺条件对复合材料的力学性能有很大的影响,在成型温度190℃、成型压力10MPa、保压时间10 min时制备的复合材料力学性能最佳,此时拉伸强度为267 MPa.运用有限元分析软件对最佳工艺条件下制备的复合材料进行拉伸过程计算机模拟,得出材料的模拟拉伸变形图,并与实际拉伸情况进行对比.有限元模拟表明,断裂发生在试件的平直段端部附近,采用此最佳工艺制备玄武岩/PP复合材料具有可靠性.     

A constitutive model for OSB and its application in finite element analysis

Experiments were conducted to determine some of the material properties of OSB. Tests covered three in-plane board directions and the through thickness direction. Results showed that OSB is an orthotropic material with better material properties in the direction of strand orientation. OSB in tension behaves almost linearly up to failure, whilst in compression it exhibits plasticity. This plasticity needs to be taken into account in nonlinear finite element analysis in order to simulate the structural behaviour of OSB appropriately. An elasto-plastic constitutive model for OSB in compression was established, based on the statistics of test results. The model was used in the FE simulation of a load test on a compression specimen and a nonlinear buckling analysis of an OSB webbed timber I-beam. The close prediction of behaviour of both specimens was considered to act as validation of the proposed constitutive model.

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Ein grundlegendes Modell für OSB und seine Anwendung in der FE-Analyse

Zusammenfassung Versuche zur Bestimmung einiger Materialeigenschaften von OSB wurden durchgeführt. Die Versuche umfassten Prüfungen in drei Richtungen der Plattenebene, sowie eine Prüfung quer zur Plattenebene. Die Ergebnisse zeigten, dass OSB ein orthotropes Material mit besseren Materialeigenschaften in Richtung der Spanorientierung ist, während es sich bei Zugbeanspruchung hingegen plastisch verformt. Dieses plastische Verhalten muss bei nicht-linearen Berechnungen berücksichtigt werden, um das Festigkeitsverhalten von OSB richtig zu simulieren. Auf Grundlage der statistischen Versuchsergebnisse wurde ein elasto-plastisches Modell für OSB unter Druckbeanspruchung entwickelt. Das Modell wurde für die FE-Simulation eines Druckversuches und eine nicht-lineare Knickberechnung eines I-Balkens mit OSB-Steg verwendet. Die gute Übereinstimmung der Ergebnisse in beiden Fällen bestätigte die Eignung des Modells.

     

Application of finite element analysis to panel warping

A three-dimensional finite element program was developed to study the warping of an orthotropic plate. Special features of this program include the capability of modeling moisture-gradient-induced deformation of homogeneous as well as layered sheet materials such as plywood and fiberboard or particleboard. This specially developed finite element analysis is applied here to predict the warping due to an assumed moisture content gradient of a solid wood panel (Douglas fir). How well this analysis simulates the actual behavior of the material can only be determined on the basis of further experimental examination, which, however, was not the subject of this study.     

剑杆织机电磁离合器与制动器弹簧片的有限元计算与设计

根据波形弹簧片的结构特点与受力情况,建立了波形弹簧片的受力的数学力学模型,应用有限元法计算出片中各节点的应力与变形,确定了弹簧片的波形曲面尺寸,以此为依据制造出冲压模具及波形弹簧片,各项技术指标达到进口产品性能,实现了该产品的国产化。