电动滑板桥轻量化优化设计

本文通过SolidWorks建立参数化的电动滑板桥三维模型,导入ANSYS Workbench中进行静力学分析,根据分析的应力、应变结果,进行拓扑优化,得到合理的拓扑结构。结合拓扑优化结果和工程经验,以质量最小为目标函数,强度为约束条件,进行滑板桥尺寸优化设计,在保证滑板桥强度前提下,优化后的滑板桥比原滑板桥质量减少了33.33%,取得良好的轻量化效果。该优化方法为电动滑板车轻量化设计提供一种思路。     

物质点拓扑变量法在柔性机构设计中的应用

为克服柔性机构拓扑优化设计中的各类数值不稳定性问题,提出一种以物质点拓扑变量为设计变量的拓扑优化方法.物质点拓扑变量可视为节点密度概念的进一步拓展,基于修正网格无关性过滤函数提出了新的拓扑变量场插值形函数.基于弹簧模型,建立了柔性机构的多约束拓扑优化模型,推导了常见结构响应量的敏度表达式,采用移动渐进线法进行优化求解.最后通过二维数值算例验证了文中方法的可行性和有效性.     

走进结构拓扑优化

结构拓扑优化是最近几十年里最热门的理论研究领域之一.结构拓扑优化设计方法的重大意义就在于,改变传统的经验设计和直觉设计方法,而是通过设定目标函数、设计变量、约束条件,建立数学模型进行自动的优化设计,从而得到最优设计方案.通过各国理论研究工作者几十年不懈的努力,结构拓扑优化已经具有了很强的实用价值,并诞生了一些可以辅助进行结构拓扑优化设计的软件产品,Altair的OptiStruct就是其中的代表.     

基于ANSYS的天车主梁结构设计及拓扑优化

为实现面向酿造工艺流程的智能天车主梁轻量化设计,本文首先根据天车实际运行工况得到主梁基本结构的参数,采用SolidWorks建立主梁三维模型,利用ANSYS Workbench对主梁在5种不同工况下进行静力学分析;其次在静力学分析基础上,采用变密度法对主梁进行拓扑优化设计,并对新型主梁进行静力学分析,验证了新结构的可行性;研究结果表明,优化后的主梁不仅满足强度刚度的要求,而且主梁质量减轻约11％,腹板质量减轻约23％,优化效果显著.     

基于Ordered-RAMP模型的热固耦合结构多材料拓扑优化方法

针对传统单材料热固耦合拓扑优化设计难以实现结构材料与性能综合最优的问题,提出一种基于变密度理论有序材料属性有理近似模型的多材料拓扑优化方法.该方法通过搭建比例系数与平移系数,将多种材料属性采用[0,1]连续分布的单设计变量进行描述,并研究和比较与有序固体各向同行惩罚微结构模型的优缺点;其次借助归一化加权方法定义以结构柔度最小化和散热弱度最小化为目标函数的数学模型.结合设计变量敏度分析,详细推导多材料、多目标条件下热固耦合结构拓扑优化的迭代公式.通过数值算例分析对比了不同权系数以及不同材料属性组合对优化结果的影响;结果表明,所提出的优化方法在热固耦合结构多材料多目标拓扑优化设计中具有可行性和有效性.     

自转旋翼机龙骨多目标优化设计

建立自转旋翼机龙骨的有限元模型,对自转旋翼机龙骨进行静力分析。以自转旋翼机龙骨的各个结构管的截面尺寸作为设计变量,以自转旋翼机的总质量为设计目标,运用ANSYS优化模块对自转旋翼机的轻量化设计进行初步研究。基于优化设计软件iSIGHT,通过试验设计和有限元分析结构建立龙骨设计变量与优化目标的径向基函数神经网络模型。利用NSGA-Ⅱ优化算法进行求解,完成对自转旋翼机龙骨的优化。     

基于ANSYS Workbench的停车顶检测车底架优化设计

运用三维设计软件SolidWorks建立了停车顶检测车底架的参数化模型,利用ANSYS Workbench软件对原有底架进行了静力学分析和形状优化设计,然后建立尺寸优化设计数学模型,对底架进行了响应面分析和灵敏度分析,运用多目标遗传算法(MOGA)对形状优化后的模型进行了尺寸优化设计,两次优化设计后的底架,质量降低了34％,实现了检测车底架结构的轻量化设计,节约了搬运过程中的人力物力,降低了工程造价,同时为以后类似结构的设计提供了参考依据.     

基于OptiStruct的望远镜主框架拓扑优化设计

针对某航空望远镜主结构的重量过高的问题,提出了对航空相机望远镜主框架进行拓扑优化设计的方法.基于拓扑优化理论,在重力过载的工况下对望远镜主框架拓扑优化,以整个框架作为设计变量,以框架的体积分数和固有频率作为约束条件,选结构的柔度最小化为目标函数,建立拓扑优化模型.采用MSC.PATRAN/NASTRAN软件对航空望远镜拓扑优化结果进行仿真,分析结果表明,结构的重量减少了77%,结构静态刚度提高,动态刚度符合要求,温度变化环境下光学成像条件改善.     

梁式称重传感器弹性体的固有频率的提高及结构参数优化

合理的结构参数组合能够提高悬臂梁式称重传感器弹性体的固有频率,并且能够改善传感器的响应特性。先通过Solidworks参数化建模软件建立悬臂梁式称重传感器的参数化三维模型。为实现参数传递不丢失,再建立Solidworks与ANSYS Workbench的无缝连接。在对悬臂梁式称重传感器进行模态分析的基础上,基于ANSYS Workbench的优化设计功能模块,对其进行优化计算分析,通过计算、分析相关参数对优化目标的敏感性和输入参数对优化目标的响应,来确定最佳的优化方案,并与原方案比较,结果表明:优化后的传感器固有频率提高了2. 47%,达到了优化目的。     

基于单元生死功能的转向架构架拓扑优化设计

为了更好地实现转向架构架的轻量化设计,根据设计经验,采用渐进结构优化法(ESO)的基本思想,通过对ANSYS单元生死功能的二次开发,应用APDL(ANSYS Parametric Design Language)编制拓扑优化程序,以直观的有限元模型代替复杂的拓扑优化的数学模型,提出了一种构架拓扑优化设计的工程方法。通过方法优化,使某高速动力车转向架构架在疲劳强度符合要求的前提下,结构应力趋于均匀分布,质量减少了143.92kg。结果表明,提出的方法是有效的和可行的,具有一定的工程实用价值,为设计提供依据。     

基于ANSYS Workbench的低温储罐多目标优化设计

为更加高效合理地设计质量更小的低温储罐,应用ANSYS Workbench中的Design Modeler模块建立某低温储罐外容器的有限元参数化模型,并对该设备进行特征值屈曲分析,得到其临界外压载荷。考察相关结构参数的影响,在此基础上利用多目标驱动优化分析得出在满足临界屈曲压力要求下的最优加强结构,实现设备的轻量化设计。     

基于ANSYS的吸附式擦黑板机器人关键结构分析

基于ANSYS,通过使用有限元分析的方法,对吸附式擦黑板机器人进行结构分析,并提出优化结构的方案.采用SolidWorks和ANSYS软件相结合的方法,利用SolidWorks构建出吸附式擦黑板机器人的三维模型后导入ANSYS Work?bench中,通过ANSYS对模型进行有限元仿真分析,求出底盘在施加载荷的情况下的最大变形量及最大应力所在位置,通过仿真分析结果对该机器的结构强度进行分析,验证结构的合理性,并提出优化方案,重复上述过程验证优化方案的可行性.     

基于无网格局部Petrov-Galekin法的板结构拓扑优化

为将无网格法的优势集成到结构拓扑优化中,基于无网格局部Petrov-Galerkin(Meshless Local Petrov-Galerkin,MLPG)法进行板结构的拓扑优化.基于带惩罚的各向同性固体微结构(Solid Isotropic Microstructure with Penalization,SIMP...     

Simultaneous shape and topology optimization of shell structures

In this research, Method of Moving Asymptotes (MMA) is utilized for simultaneous shape and topology optimization of shell structures. It is shown that this approach is well matched with the large number of topology and shape design variables. The currently practiced technology for optimization is to find the topology first and then to refine the shape of structure. In this paper, the design parameters of shape and topology are optimized simultaneously in one go. In order to model and control the shape of free form shells, the NURBS (Non Uniform Rational B-Spline) technology is used. The optimization problem is considered as the minimization of mean compliance with the total material volume as active constraint and taking the shape and topology parameters as design variables. The material model employed for topology optimization is assumed to be the Solid Isotropic Material with Penalization (SIMP). Since the MMA optimization method requires derivatives of the objective function and the volume constraint with respect to the design variables, a sensitivity analysis is performed. Also, for alleviation of the instabilities such as mesh dependency and checkerboarding the convolution noise cleaning technique is employed. Finally, few examples taken from literature are presented to demonstrate the performance of the method and to study the effect of the proposed concurrent approach on the optimal design in comparison to the sequential topology and shape optimization methods.     

Design optimization of a runflat structure based on multi-objective genetic algorithm

Runflat structure plays an important role in determining the sustainable mileage after the tire is shot. Lightweight, stiffness and strength are highly relevant to the overall performance of the structure. A parameterized model was built based on the full study of the structure, and a new adaptive meshing method is proposed to ensure the quality of the model. The accuracy of the new model was verified by comparing to the traditional finite element model. The parameter study was carried out to investigate the response of the performance and mass. Multi-objective optimization model was established by applying optimal Latin square design method and response surface model approach. Non-dominated sorting genetic algorithm-II (NSGA-II) was applied to obtain the optimization design. The results indicate that the combination of parameterized model and multi-objective genetic algorithms successfully achieve the goal of multi-objective optimization for mass and displacement while ensuring the stress. Meanwhile, the optimal topology, shape and thickness optimization for the runflat structure have been achieved at the same time.     

An integrated approach for shape and topology optimization of shell structures

In this paper an automated approach for simultaneous shape and topology optimization of shell structures is presented. Most research in the last decades considered these optimization techniques separately, seeking an initial optimal material layout and refining the shape of the solution later. The method developed in this work combines both optimization techniques, where the shape of the shell structure and material distribution are optimized simultaneously, with the aim of finding the optimum design that maximizes the stiffness of the shell. This formulation involves a variable ground structure for topology optimization, since the shape of the shell is modified in the course of the process. The method has been implemented into a computational model and the feasibility of the approach is demonstrated using several examples.     

On simultaneous shape and material layout optimization of shell structures

This work presents a computational method for integrated shape and topology optimization of shell structures. Most research in the last decades considered both optimization techniques separately, seeking an initial optimal topology and refining the shape of the solution later. The method implemented in this work uses a combined approach, were the shape of the shell structure and material distribution are optimized simultaneously. This formulation involves a variable ground structure for topology optimization, since the shape of the shell mid-plane is modified in the course of the process. It was considered a simple type of design problem, where the optimization goal is to minimize the compliance with respect to the variables that control the shape, material fraction and orientation, subjected to a constraint on the total volume of material. The topology design problem has been formulated introducing a second rank layered microestructure, where material properties are computed by a “smear-out” procedure. The method has been implemented into a general optimization software called ODESSY, developed at the Institute of Mechanical Engineering in Aalborg. The computational model was tested in several numerical applications to illustrate and validate the approach.     

基于子结构和模式重复的地铁车辆座椅支架 拓扑优化

针对地铁车辆座椅模型加载范围广和座椅支架结构对称的特点,在进行地铁车辆座椅支架拓扑优化时,采用SIMP理论建立数学模型,同时引进子结构和模式重复方法,优化得到符合设计要求的结构。对比结果认为：优化后的地铁车辆座椅支架质量减轻49%,地铁车辆整体的强度性能增强,可达到地铁车辆座椅支架轻量化的目标。     

履带车辆扭杆弹簧有限元模型与优化

扭杆弹簧是车辆悬挂(架)装置中常用的弹性元件。该文利用有限元方法对扭杆弹簧进行了建模，给出了扭杆弹簧的结构应力分布规律，在此基础上，对原结构存在的问题，提出了改进方案并进行了有限元的优化计算分析。分析结果表明，所提出的改进结构优于原结构，其研究结果对扭杆弹簧的优化设计具有指导意义。     

基于无网格径向点插值方法的简谐激励下的连续体结构拓扑优化

针对用有限元法进行连续体结构拓扑优化时需不断重构网格来处理网格畸变和网格移动,且存在数值计算不稳定等问题,基于无网格径向点插值方法(Radial Point Interpolation Method,RPIM)对简谐激励下的连续体结构进行拓扑优化.选取节点的相对密度作为设计变量,以结构动柔度最小化为目标函数,基于带惩罚的各向同性固体微结构(Solid Isotropic Microstructure with Penalization,SIMP)模型建立简谐激励下的优化模型;采用伴随法求解得到目标函数的敏度分析公式;利用优化准则法求解优化模型.经典的二维连续体结构拓扑优化算例证明该方法的可行性和有效性.