ANSYS软件中施加扭矩的方法

在机械结构的有限元分析中,常会遇到施加扭矩的问题。文中探讨了在ANSYS软件中施加扭矩的一种方法,以在一个六棱柱一端施加扭矩为实例,说明了ANSYS施加扭矩方法的过程。     

基于接触单元的扭矩施加法

扭矩是ANSYS中常见的一种载荷。传统方法采用若干对集中力偶的方式来等效施加扭矩,往往造成集中力处的应力集中。文中对常见的扭矩施加方法进行了比较、总结,在此基础上提出了基于接触单元的扭矩施加法。通过一个实例阐明了该方法的具体步骤,探讨了一种在ANSYS中施加扭矩的方法。     

基于 ANSYS分析的减速器输出轴设计

采用ANSYS有限元方法对减速器输出轴进行分析计算。利用三维软件SolidWorks 建立轴的实体模型,并将模型导入ANSYS中,选用Solid45作为轴的单元,得到轴的有限元模型。然后在轴颈处添加刚性约束,输出端轴头处施加扭矩,齿轮处的键槽处施加载荷,完成输出轴的静强度分析和模态分析。有限元分析结果表明,该输出轴满足轴的强度、刚度和振动稳定性要求。     

基于ANSYS软件的矿井提升机主轴的数值模拟

利用ANSYS软件建立了矿井提升机主轴的有限元模型,采用将扭矩转化为多个节点上的周向集中栽荷的扭矩施加方法,在多种工况下进行数值模拟计算,实现了主轴静强度和静刚度的校核,得到了主轴的应力应变分布规律,为矿井提升机主轴结构的改进设计、寿命计算等提供了可靠数据。     

在ANSYS分析中对连续弯矩载荷的施加方法

在现有的ANSYS分析软件中没有对连续弯矩载荷的直接施加,但在实际的工程中却经常碰到这种载荷.在ANSYS中对于力的施加要比对于弯矩的施加更方便一些,文中主要通过运用ANSYS中的力载荷来模拟这种弯矩载荷以降低加载难度,并说明这种模拟的可实施性,最后用ANSYS分析结果和理论结果进行了比较.     

螺栓拧紧扭矩对其扭矩系数的影响

螺栓预紧力作为保障结构稳定运行的重要参数,其在实际工程中往往难以准确施加,因而会对钢结构连接的可靠性产生较大的影响.在实际工程中,螺栓预紧力常常通过施加预紧扭矩来控制预紧力,其中扭矩系数的选择会直接影响到预紧力施加的准确性.本文针对施加扭矩过程中扭矩系数的不确定性问题,从螺纹副受力分析出发,推导出预紧力与扭矩的理论关系...     

换热管缺陷扭转模态导波检测的仿真研究

换热管作为换热器的关键部件之一,对其进行检测至关重要。扭转模态T（0,1）超声导波具有无频散特性,在换热管检测中有广阔的应用前景。采用ANSYS 有限元方法对T（0,1）模态导波检测进行仿真研究,为克服在ANSYS中Solid 164单元无旋转自由度而无法加载转角或扭矩的问题,提出了通过施加刚体转动间接激励T（0,1）模态导波的方法。研究了转角加载和扭矩加载两种不同激励方式,仿真结果表明两种激励方式都可以成功激励出T（0,1）模态导波,缺陷定位准确,且扭转模态导波在弯管中衰减更大。     

基于ANSYS的滚珠联轴器的有限元分析

滚珠联轴器是一种新型高效的联轴器。根据非线性接触理论，借助ANSYS有限元分析软件，对滚珠联轴器在受扭矩载荷作用下的接触应力进行了分析和计算。在施加静载时，找出滚珠联轴器产生接触应力最大值的区域，并计算在不同结构参数下的应力值，分析滚珠联轴器的结构参数对应力值的影响情况，获得了应力值变化规律曲线，为实际应用及今后进一步分析打下了良好的基础。     

基于ANSYS联轴节的有限元分析

利用APDL语言对联轴节进行参数化建模,通过接触对建立了外套、内套与轴之间的关系,通过ANSYS软件得出了安装完毕后各部件的应力分布云图,找到了外套与内套的危险区域,得出了外套内表面、内套内外表面的径向应力沿轴线的分布曲线,通过对内套与轴的接触强度曲线的分布曲线分析,说明了联轴节连接的可靠性。在安装建模的基础上,对联轴节受扭矩时的工作状况进行了分析,通过MPC点施加扭矩,得出了联轴节整体应力云图,再次对内套与轴的接触强度进行分析,说明了传递扭矩的可靠性,为联轴节的设计提供了理论基础,为其进一步的优化设计提供了可靠的理论依据。     

基于ANSYS专用计算机机箱温度场分析与实验

建立专用计算机的三维模型后,通过Pro/ENGINEER和ANSYS软件接口将模型导入到ANSYS软件中,通过选择网格单元、设置材料特性参数、划分网格、施加载荷和边界条件、后处理等操作,得到机箱整体和关键部件的温度分布云图。通过与试验结果相比较,验证了ANSYS软件热学仿真的可行性和合理性,为设计人员对专用计算机机箱的优化设计提供了理论依据。     

一种三相变压器联结组别的巧识法

三相变压器联结组别在实际工程中应用广泛,在实际中检测很重要,而学生在学习时不太容易掌握。该文首先分析了传统判定法,然后介绍采用巧识法来判定三相变压器的联结组标号。此方法简单、易懂,在实际应用中也很方便,便于学生学习和应用,也可供相关工程技术人员借鉴。     

设计创新:促进中国制造走向中国创造

在积极推行自主创新的今天,如何促进中国制造早日走向中国创造是制造业面临的重要课题.从制造走向创造,需要技术创新,更需要好的设计创意,通过设计创造价值.在论述中国设计存在的问题基础上,探索这一命题的解决途径.     

A tension zone model of blanking and tearing of ductile metal plates

The objective of this paper is to theoretically predict the plastic resistance and the plastic work in blanking and tearing of ductile metal plates. It is found that shear resistance in blanking of metal plates is attributed to two factors. First, there are large rotations of material elements in the shear zone. These rotations give rise to large tensile deformation in a direction oblique to the shear surface. The Tension Model is developed to determine the role of this factor in blanking tests and the shear load instability is revealed. The other factor is due to the reduction of shear area caused by the crack propagation through the thickness. With the Tension Model as a representative element, the Blanking Model with a moving fracture front is proposed to predict the shear force, the plastic work, and the shape and size of the plastic shear zone. Good agreement is found with the published experimental results for a variety of materials by other investigators. Finally, the three-dimensional tearing process is modeled as a two-dimensional blanking problem. Then the Blanking Model is applied to the plate tearing to determine the specific work of fracture.     

基于预测的立体视觉/力反馈研究

提出了一种多传感器混合的机器人伺服控制方案 ,该方案在任务初始阶段利用视觉传感器对对象进行跟踪 ,在任务的末段利用力传感器对对象运动进行引导。这样就避免了使用单个传感器所产生的强冲击 ,增加了机器人控制的柔顺性和鲁棒性。在视觉跟踪阶段 ,为了提高跟踪速度 ,利用约束卡尔曼滤波器建立预测器 ,对物体图像的未来位置进行预测 ,这样就减小了图像处理的区域 ,提高了图像处理的速度。从仿真结果来看 ,视觉 /力反馈的混合控制提高了机器人对任务的适应性和工作过程的柔顺性。     

Application of a hybrid simulated annealing-mutation operator to solve fuzzy capacitated location-routing problem

In the field of supply chain management and logistics, using vehicles to deliver products from depots to customers is one of the major operations. Before using vehicles, optimizing the location of depots is necessary in a location-routing problem (LRP). Also, before transportation products, optimizing the routing of vehicles is required so as to provide a low-cost and efficient service for customers. In this paper, the mathematical modelling of LRP is developed according to the existing condition and constraint in the real world. Maximum travelling time constraint is added, and we apply fuzzy numbers to determine customer demands, travelling time and drop time. The objective is to open a subset of depots to assign customers to these depots and to design vehicle routes, in order to minimize both the cost of open depots and the total cost of the routes. The proposed problem is modelled as a fuzzy linear programming (FLP), by applying the fuzzy ranking function method; the proposed FLP is converted to an exact linear programming (LP). A Lingo solver is used to solve this LP model in very small size. LRP is an non-deterministic polynomial-time hard (NP-Hard) problem, and because of the limitation of Lingo solver in solving medium, and large-size numerical examples, a hybrid algorithm including simulated annealing and mutation operator is proposed to solve these numerical examples. Also, a heuristic algorithm is proposed to find a suitable initial solution which is used in hybrid algorithm. At the end, a different analysis of the applied algorithm and a proposed model are introduced.     

脉冲涡流方法过油管检测套管横向裂缝研究

油井套管横向裂缝是可能导致套管断裂的严重危害性缺陷。通过有限元仿真与实际试验,研究利用脉冲涡流检测技术使用横向探头通过油管检测套管的横向裂缝缺陷的问题。仿真给出不同检测方式的管道涡流分布、磁场分布及其变化,以及接收线圈的电压。从仿真结果可观察出,套管壁涡流最强的区域并非横向探头正对的区域,而是平行于横向探头轴线的区域。横向裂缝平行于横向探头轴线时对涡流场的扰动最大。磁场的分布及其变化规律与涡流场情况类同。据此可解释为何横向探头轴线平行于横向裂缝时检测灵敏度会高于横向探头轴线垂直于横向裂缝时。实际的检测试验结果与仿真结果一致,并且显示了实际检测中横向探头轴线平行于横向裂缝时的检测灵敏度显著高于垂直于裂缝时。     

Numerical investigation on the directionality of nonlinear indicial responses

An unsteady Euler solver is modified to investigate the directionality of nonlinear indicial response to a step change in the angle of attack. An impulsive change in the angle of attack is incorporated by using the field velocity approach, which is known to decouple the step change in the angle of attack from a pitch rate. Numerical results are thoroughly compared against analytical results for two-dimensional indicial responses. The same method is applied to investigate the directionality of nonlinear indicial responses. It is found that directionality is mainly due to the asymmetry of initial shock locations. Since the directionality of the pitching moment responses is significant in the critical Mach number region, it is also shown that consideration of the directionality is crucial for accurate modeling of the nonlinear indicial functions.     

Field-ion microscopy of iron-molybdenum solid solutions

The average density of bright spots in the (200) region of field-ion microscope images is found to be related to the nominal molybdenum composition in a series of iron-molybdenum alloys containing 1/2 to 5 weight percent molybdenum. The bright spot density is found to be proportional to the square of the tip radius and is thus linearly related to the surface area. This indicates that a correlation between the observed bright spot density and a bulk property is permissable. The bright spot density is also found to increase approximately linearly with molybdenum content, at least up to 3% molybdenum. Observation of specimens with similar amounts of molybdenum in solid solution but different nitrogen contents shows that the observed correlation is independent of the nitrogen content. Similarly, it is shown that the correlation is also independent of carbon content. Thus, it is concluded that the bright spot density is directly related to the amount of molybdenum in solid solution and can be used as a measure of the local molybdenum concentration. The nature of the bright spot contrast is discussed and is shown to be consistent with a current theory of image formation.     

Detection of minute signs of a small fault in a periodic or a quasi-periodic signal by the harmonic wavelet transform

If a machine in operation has a fault, signs of the fault appear in the monitored signal and are usually synchronised with the operating speed. The signs are very small when the fault is at an early stage. The fast Fourier transform (FFT) is often utilised to detect these signs, but it is very difficult to detect minute signs. In this paper, harmonic wavelet transform is utilised to detect the minute signs of small faults in a monitored signal. The monitored signal of a machine element, in ordinary operation, is regarded as periodic or quasi-periodic. It is important for the effectual detection of the minute signs to reduce the obstructive noise and the end effects in the signal. The end effect is a peculiar phenomenon to wavelet transform and hampers effective detection. Useful methods to reduce the obstructive noise and the end effects are devised herein by the authors. Even if no visible information pertaining to a fault appears in the monitored waveform, the present method is able to detect a minute sign of a small fault. It is demonstrated that the present method is capable of detecting minute signs arising from slight collisions caused by a loose coupling and a fatigue crack.     

加载路径对弯曲件回弹影响的机理

通过对弯曲件加栽和卸载路径及横截面切向应力分布图进行分析,通过作图法定性地分析了弯曲回弹产生和控制的机理。论述了加载和卸载路径对弯曲回弹的影响机理。详细分析了拉弯中预拉力法和补拉力法申加载和卸载的路径及对弯曲件回弹的影响,指出了它们对控制回弹作用的不同,预拉力主要用于防止弯曲起皱,补拉力的作用是减小弯曲件的回弹。对工艺人员采用不同的方法控制回弹具有指导意义。