直齿圆柱齿轮的三维建模及有限元分析

以Pro/E为开发平台,Pro/Program为开发工具,对标准直齿圆柱齿轮的参数化建模进行了详细的介绍.只要按提示输入标准直齿圆柱齿轮的5个基本参数,就可以得到精确的直齿齿轮的三维实体.同时利用ANSYS有限元分析软件的特点,可以在不脱离Pro/E和ANSYS这两个软件的情况下对直齿圆柱齿轮进行有限元分析.     

风力发电机风轮叶片三维有限元建模研究

随着风力发电机单台功率的不断提高,风轮叶片越来越大,为达到增加强度和减轻质量的目的,叶片的铺层设计越来越复杂,致使层合材料沿叶片弦向和展向分布极不规律,这给风轮叶片的三维有限元建模带来了很大的麻烦.针对这个问题,给出了一种建立有限元模型的方法,通过坐标转换、铺层判断等子程序,自动完成层合单元的属性设置.该方法并未针对具体的风机型号及具体的有限元计算软件设计,因此具有一定的通用性.     

热流道板的热平衡及温度场的有限元分析

热平衡是热流道系统的核心问题之一,热流道板的主要任务是恒温地将熔体从主流道送入各个单独喷嘴.热流道板必须处于热平衡状态,热损失必须通过加热来补偿.通过分析热流道板的热损失,进行加热器功率的计算,并利用ANSYS软件分析热流道板的温度场.     

一种快速计算二维缺陷漏磁场的有限元建模和求解方法

漏磁检测的速度快,灵敏度高,检测过程操作简单,是一种常用的铁磁材料无损检测方法,其中有限元模型被广泛用于漏磁检测中。有限元模型的求解精度高但是计算时间较长,因此,本文提出了一种快速计算二维缺陷漏磁场的有限元建模和求解方法,在保证精度的同时缩短计算时间。通过对有限元数值计算的理论推导,建立了漏磁场的有限元模型,首先采用六节点三角形单元划分网格,其次使用稀疏矩阵的形式求解方程组,再利用边界条件矩阵零空间的正交基求解出磁势。与COMSOL仿真软件的计算结果进行比较,表明本文所建模型是正确可行的。经过实测数据验证,该模型相比于传统有限元模型有明显的性能提升,精度上最大提高83.49%,计算时间能减少95.43%,为研究不规则缺陷的漏磁重构提供了快速有效的正演模型。     

DLF与SLM激光快速成型方法的比较研究

分别采用激光直接制造(DLF)技术和选择性激光熔化(SLM)技术对不锈钢材料进行一系列的激光快速成型实验,根据实验结果,对比分析DLF和SLM两种方法在成形机理、成型精度、成型效率、适用场合、成型件的力学性能和组织结构等方面的异同。结果表明,SLM技术的成型精度要优于DLF技术;两者成型件都具有较高的力学性能,均优于普通不锈钢;SLM与DLF成型件组织性能基本相同;如果切片层厚相同,SLM的成型效率高于DLF;DLF主要用于粗加工或零件修复等场合,而SLM可用于精密、复杂零件的制造。     

高速切削温度场的三维有限元建模与动态仿真

根据温度场控制方程及其边界条件,建立高速切削的三维有限元分析模型,将切削过程的温度分布和变化情况以及切削速度、进给量和切屑厚度等对切削温度的影响进行仿真分析,与相同切削条件下的二维仿真结果和实际测试结果进行对比,可以得出结论:三维建模仿真得到的高速切削温度变化趋势与相关文献结果基本一致,但三维仿真获得的温度值比二维仿真要高些,并且三维仿真的温度值更接近于实际测量值。     

基于ANSYS的二维结构声场混合有限元模型研究

为了求解复杂结构体下的声场分布,采用ANSYS软件建立了声场-结构二维混合有限元模型,给出了ANSYS软件中混合模型的建模方法,通过在结构体四周设置结构体与空气耦合单元,将结构模型因受力发生形变而产生的噪声声压耦合到空气中,实现了混合声场模型的求解。模型求解结果表明,该模型能很好地解决声场与结构场的耦合问题。     

Comparative two- and three-dimensional finite element modelling techniques for tibial fractures

Often the choice of a two-dimensional modelling approach over a three-dimensional approach is made on the basis of available resources, and not on task appropriateness. In the case of simulating the mechanical behaviour of irregular anatomical structures in biomedical engineering, the authenticity of two-dimensional model behaviour and the interpretation of model solutions is of particular concern since little comparable two-dimensional and three-dimensional data have been published. As part of a research programme, a comparison was made between two-dimensional and three-dimensional finite element models (FEMs) that examine the stress-strain environment of a clinical bone fracture and callus. In comparison with the three-dimensional model, the two-dimensional model substantially underestimated peak compressive principal stresses in the callus tissue and peak equivalent strains. This was a consequence of geometrical and structural asymmetry in a plane perpendicular to the two-dimensional model. However, the two-dimensional model predicted similar patterns of stress and strain distribution to the corresponding mid-longitudinal plane of the three-dimensional model, and underestimates of peak stress and strain were much reduced. This confirmed that despite the irregular geometry and structure of the subject, the two-dimensional model provided a valid mechanical simulation in the plane of the fracture that it represented.     

Segment-to-segment contact elements for modelling joint interfaces in finite element analysis

This paper presents an efficient approach to model contact interfaces of joints in finite element analysis (FEA) with segment-to-segment contact elements like thin layer or zero thickness elements. These elements originate from geomechanics and have been applied recently in modal analysis as an efficient way to define the contact stiffness of fixed joints for model updating. A big advantage of these elements is that no global contact search algorithm is employed as used in master–slave contacts. Contact search algorithms are not necessary for modelling contact interfaces of fixed joints since the interfaces are always in contact and restricted to small relative movements, which saves much computing time. We first give an introduction into the theory of segment-to-segment contact elements leading to zero thickness and thin layer elements. As a new application of zero thickness elements, we demonstrate the implementation of a structural contact damping model, derived from a Masing model, as non-linear constitutive laws for the contact element. This damping model takes into account the non-linear influence of frictional microslip in the contact interface of fixed joints. With this model we simulate the non-linear response of a bolted structure. This approach constitutes a new way to simulate multi-degree-of-freedom systems with structural joints and predict modal damping properties.     

Subarea simulation and distributed computing of direct laser fabrication

Recently, the researches on the relationships among parameter, temperature, thermal stress, and residual thermal stress in direct laser fabrication (DLF) are extensively conducted. However, it takes a long time to simulate the large-scale workpiece, and thus, the studies on simulations are still limited to small test parts. This paper presents an original idea that the large-scale workpiece is substituted by subarea simulation for DLF finite element model. In simulating the workpiece DLF, we have established two groups of models to which two discrepant approaches are applied. Unlike the traditional time-consuming methods for intact simulation, our subarea simulation method saves a large amount of time and internal memory, which is vital for the large-scale simulating process. Our novel approach shows that a large-scale workpiece can be divided into several subareas for simulation such that finite element computation can be distributed to a certain number of computers working simultaneously. The experimental results verify that our approach benefits the subarea simulation as well as the distributed computation of DLF.     

箱形主梁的三维参数化设计及有限元分析

根据QD系列桥式起重机箱形主梁的结构特点，介绍了基于SolidWorks平台的箱形主梁三维参数化设计方法，并实现了箱形主梁与有限元分析软件ANSYS之间的程序接口。对于设计人员来说，具有一定的参考价值和现实意义。     

结晶器三维温度场可视化系统实现

连铸漏钢是连铸生产工序的主要故障之一.目前,漏钢预报系统仅根据有限的温度采集数据随时间变化的二维曲线,操作人员无法了解采集点外区域的温度情况.本文主要介绍了三维温度场可视化系统的组成和实现方法.通过分析结晶器铜板的传热原理,建立热传导温度模型,确定边界条件.与实测温度值相比较,数值结果表明温度场模型的有效性.根据温度场模型的计算结果,用Microsoft Visual C+ + 6.0工具和有限元分析软件ANSYS开发了结晶器三维温度场可视化系统,作为漏钢预报的辅助判断手段和分析决策平台.     

基于质量限制的全钢活塞三维有限元分析

为满足发动机向高功率密度(HPD)方向发展的需要,设计了一种新型全钢活塞,利用有限元软件MSC.NASTRAN对其进行热负荷、机械负荷以及热负荷和机械负荷共同作用下的分析计算,并与传统铝活塞在重量上进行了对比,为全钢活塞的结构分析和改进提供了参考。     

从动齿轮去毛刺三维有限元分析

利用ANSYS软件对粉末冶金材料的从动齿轮毛刺进行有限元分析,根据改变去毛刺载荷的作用方法（由角度θ和φ决定）所得到的应力分布曲线,得出去毛刺得最佳效果时的最佳角度θ和φ,为设备的设计和改进提供了指导。有限元分析模型为粉末冶金产品去毛刺分析提供了合理参考。     

基于ANSYS的激光清洗模具表面温度场有限元分析

激光清洗是一种新型的工业清洗技术,它利用激光能量将模具表面的污垢去除,达到绿色清洗的目的。文章利用ANSYS软件模拟了激光清洗模具过程中模具表面的温度变化,在分析过程中采用二维单元,并考虑了材料的热物性随温度的变化,建立了有限元模型,得出了模具表面节点的温度分布,以及激光功率和扫描速度对温度场的影响,这对进行激光清洗模具技术的机理研究具有很大的帮助。     

铝热精轧轧制区温度场三维有限元模拟

根据某铝热连轧厂生产线实际结构参数和工艺参数,应用弹塑性有限元法,考虑轧件金属塑性变形热、摩擦热、界面接触热导等对轧件和轧辊传热的影响,运用大型通用有限元分析软件MSC.Marc建立了铝热连轧精轧机组F2机架的热力耦合三维有限元仿真模型.通过分析轧件温度场的分布规律,为更好地控制轧件的温度分布、提高产品的质量提供依据.     

基于三维非线性有限元的液压扳手的优化改进设计

阐述和分析了应用有限元方法进行结构优化改进设计的基本原理和所涉及的关键问题。考虑非线性接触问题，对液压扳手进行了有限元优化的计算分析与研究，得到了优化的形状与尺寸，结构的特性与受力状况得到明显改善。     

三维接触有限元分析在产品设计中的应用

接触应力是不易检测、难于计算,但对于设计又是非常重要的一个难题.尝试用ANSYS中的接触单元对汽轮机中叶片与叶轮的接触强度进行详尽的分析,同时探讨了与迭代计算收敛性及计算结果可靠性有关的几个难点和要点问题.该三维接触有限元分析方法也可用于其它机械产品的接触强度分析,为机械产品由单个零件的强度分析提升到装配体的强度分析提供参考.     

3D finite element modeling of face milling of continuous chip material

Milling operations are very common in manufacturing. Often it represents the last operation, determining the final product quality. Then an accurate mathematical model is important in order to design the cutting process, in terms of cutting process, and the geometry of the insert, for tool manufacturers. The finite element modeling (FEM) simulation permits the prediction of the cutting forces, stresses, and temperatures of the cutting process. The 2D FEM can be a reasonable approximation, where the deformation can be considered plain. For the milling operations, this assumption can be suitable if the depth of cut is much bigger than nose radius. But in the normal situation the insert has a complex geometry and the bidimensional model of the milling operation is not appropriate. The 3D FEM involves different element formulations, different remeshing algorithm, and different boundary conditions, so an independent approach is necessary. The approach followed in this paper is to model three-dimensionally the milling operation, considering the real geometry of the insert. The FEM simulation is carried out with a commercial code (3D DEFORM?). First the rheological model has been calibrated using OXCUT software, developed at the ERC/NSM, and a sensitivity analysis about friction model has been performed. Milling tests are conducted and the measured cutting forces are compared to finite element modeling results. The results show an acceptable agreement with experimental results in the range of cutting speed and feed rate considered.     

AC接触器电磁机构的三维有限元分析

以GSC3型交流接触器为例,将有限元法应用于其磁系统的数值计算中,得到各状态下磁系统的磁场分布图形及不同气隙、电流下的电磁吸力,同时对仿真结果进行分析,为后续AC接触器的动态仿真提供数据支持。