基于MATLAB的亥姆霍兹线圈轴线磁场均匀分布的动态仿真

MATLAB软件为复杂、抽象物理现象的动态仿真提供了简单、高效的编码环境.文章在分析亥姆霍兹线圈轴线磁场分布现象的数学模型基础上,提出了一种运用MATLAB软件对亥姆霍兹线圈轴线磁场均匀分布进行验证及仿真的方法.该方法能够简便、直观地展现亥姆霍兹线圈轴线磁场均匀分布的这一物理现象.     

圆环电流及亥姆霍兹线圈磁场的一种数值解法

直接从毕奥—萨伐尔定律出发,用MATLAB语言计算圆环电流及亥姆霍兹线圈的磁感应强度,并绘制磁感应线分布图和磁感应强度的空间分布图.     

圆电流和亥姆霍兹线圈磁场的数值模拟

根据毕奥-萨伐尔定律和磁场叠加原理,导出圆电流和亥姆霍兹线圈的磁场分布含积分的表达式。利用Mathematica软件进行数值计算,得到磁场分布的数值解,由此绘出圆电流和亥姆霍兹线圈的磁场分布图像,并对两者的磁场均匀区进行分析比较：在垂直于中心轴线平面上亥姆霍兹线圈磁场均匀区的面积是圆电流的10.4倍;在轴平面上前者是后者的5.4倍。最后对亥姆霍兹线圈磁场均匀区（±1%）作对比分析,数值计算的结果与相关实验测量十分吻合。     

正方形亥姆霍兹线圈的磁场

将正方形载流线圈视为四段载流导线,采用分段计算然后叠加的方法,导出了正方形载流线圈中心轴线上磁场分布的一般表达式.在此基础上,以圆形亥姆霍兹线圈的理论为基础,计算了正方形亥姆霍兹线圈轴线上的磁感应强度,并分析了磁场的均匀性.     

实验室中用多线圈获得匀强磁场设计的思考

在物理实验中，研究匀强磁场有重要作用。通过研究与比较单线圈、亥姆霍兹线圈、三线圈的磁场，得出三线圈的磁场在均匀性和强度上均超过了单线圈和亥姆霍兹线圈。     

亥姆霍兹线圈磁场均匀性的研究

用Mathematica研究了亥姆霍兹线圈中心区域磁场的均匀性.给出了多种区域所对应的Bx(x,y)和By(x,y)的三维分布图,从而求出了这些区域内磁场的均匀度.     

亥姆霍兹线圈磁场测量实验数据处理方法改进

亥姆赫兹线圈磁场测量实验是电磁学实验教学中的重要内容,是研究霍尔效应法测量磁场的重要手段。该文利用Origin9.1软件的误差分析、绘图、拟合等功能处理"亥姆霍兹线圈磁场测量"实验数据,最终得到载流圆线圈轴线上磁场的分布,加深对毕奥—萨伐尔定律的理解,为实验提供一种高精确度的数据处理方法。     

亥姆霍兹线圈可调频宽带震源设计

亥姆霍兹线圈是两个完全相同的薄的平行的线圈组成,两线圈的匝数与线圈的半径相等,两线圈的信号串联起来,在亥姆霍兹线圈中置入永磁体,形成震源;设计具有效率高、体积小、带宽宽、余振短、穿透距离远、重复性好的特点,设计经实验探测及数据采集和处理,理论与实践基本一致。     

基于MATLAB的空间电磁分布可视化研究

本文讨论了电磁场与电磁波实验教学中利用Matlab的3D绘图功能，对相关二、三维现象进行可视化处理的方法，绘制了亥姆霍兹线圈磁场空间分布的3维图形，并讨论了利用Matlab视角变换功能对相关问题进行分析的方法。     

用有限元仿真计算法研究螺线管制动器内磁场分布

采用ANSYS有限元分析软件对螺线管制动器结构进行有限元分析,将螺线管制动器三维轴对称模型简化为二维平面模型,确定单元网格划分模型和有限元模型的边界条件等计算参数,对磁场分布进行仿真计算,求出衔铁部分(螺线管制动器的运动部分)受力情况、线圈电感和电压激励下的线圈电流等,使螺线管制动能力的计算变得快捷而有效。     

基于MATLAB平面桁架有限元分析研究

基于平面桁架有限元分析的基本原理,利用MATLAB软件对某平面桁架编制了计算程序,得到了结构的内力计算结果、变形图和结构的动力特性,并将计算结果与ANSYS有限元分析软件的结果进行比较.结果表明,二者的计算结果一致.利用MATLAB可以编制结构有限元分析程序,计算速度快,数据准确,并能为复杂结构有限元分析提供参考.     

Prediction for dynamic characteristics of ring-plate planetary indexing cam mechanism

This paper is aimed to propose an approach to predict the dynamic characteristics of ring-plate planetary indexing cam mechanism, which is a novel type of indexing mechanism that employs internal planetary transmission structure. Firstly, the geometry and structure of the mechanism are discussed and the kinematic practicability is simulated with virtual prototype design. Then a 3D finite element model of the ring-plate planetary indexing cam mechanism is developed with the commercial software of MATLAB and ANSYS. Through the finite element analysis, the natural frequencies and the corresponding mode shapes are predicted in one motion cycle. On the basis of the virtual prototype design and finite element analysis, an experimental prototype is made and tested to validate the prediction of the dynamic characteristics. The agreement between experimental results and the finite element analysis testifies that the finite element model developed is applicable to the prediction of the dynamic characteristics of this type of mechanism.     

Analysis and optimization of assembly variations for non-rigid parts

Traditional variation analysis methods are not applicable to non-rigid assemblies due to possible part deformation during the assembly process. This paper presents the use of finite element methods to simulate assembly deformation. The relationship between the parts＇ variation and the variation of the key points in final assembly for quality control is set up by calculating the spring back deformation after assembly. Moreover, the optimization method for non-rigid assembly variations based on finite element analysis is presented. The optimal objective is to reduce the manufacturing cost. The approach is implemented by using ANSYS and MATLAB. The test example shows that the proposed method is effective and applicable.     

ANSYS软件在砌体结构非线性分析中的应用

利用ANSYS软件建立空间模型,对轴心受压时设置构造柱的砖砌体结构进行了模拟．得到的结果与试验结果较吻合,并优于以往平面有限元的计算结果。说明可以利用ANSYS软件强大的模拟功能对砌体结构进行有限元分析．为目前日益增多的各类砌体结构提供非线性分析依据。     

Damage identification in beam-type structures using pseudo strain energy density and grey relation coefficient

Based on pseudo strain energy density （PSED） and grey relation coefficient （GRC）, an index is proposed to locate the damage of beam-type structures in time-domain. The genetic algorithm （GA） is utilized to identify the structural damage severity of confirmed damaged locations. Furthermore, a systematic damage identification program based on GA is developed on MATLAB platform. ANSYS is employed to conduct the finite element analysis of com- plicated civil engineering structures, which is embedded with interface technique. The two-step damage identification is verified by a finite element model of Xinxingtang Highway Bridge and a laboratory beam model based on polyvi- nylidens fluoride （PVDF）. The bridge model was constructed with 57 girder segments, and simulated with 58 meas- urement points. The damaged segments were located accurately by GRC index regardless of damage extents and noise levels. With stiffness reduction factors of detected segments as variables, the GA program evolved for 150 generations in 6 h and identified the damage extent with the maximum errors of 1% and 3% corresponding to the noise to signal ratios of 0 and 5%, respectively. In contrast, the common GA-based method without using GRC index evolved for 600 generations in 24 h, but failed to obtain satisfactory results. In the laboratory test, PVDF patches were used as dynamic strain sensors, and the damage locations were identified due to the fact that GRC indexes of points near damaged ele- ments were smaller than 0.6 while those of others were larger than 0.6. The GA-based damage quantification was also consistent with the value of crack depth in the beam model.     

甲板开口对船体板架构件的刚强度影响分析

甲板开口与角隅处应力集中问题和刚性问题一直倍受船舶设计人员关注。利用有限元软件ANSYS对未开口和开口的船体甲板进行有限元分析计算,比较开口与未开口的应力以及刚性,其计算结果表明开口处的应力集中相当明显。     

某高层建筑结构动力特性研究

利用有限元分析软件ANSYS对某高层建筑结构进行模态分析,建立高层建筑结构的三维模型,研究该结构的动力特性,并将计算得到结构的自振周期同经验公式比较,探讨计算高层建筑结构自振周期的影响因素,结果表明两种计算方法结果十分接近,验证了有限元分析的正确性。