基于内点罚函数法的非对称钢板弹簧优化设计

以某微客开发过程中的非对称少片变截面钢板弹簧为主要研究对象,进行钢板弹簧的优化设计及计算,建立该钢板弹簧的优化设计数学模型,并以内点罚函数法的优化设计理论为基础对钢板弹簧进行优化设计,在满足强度条件和刚度条件等约束的要求下,使钢板弹簧的质量减少,达到轻量化优化设计的目的。并将优化结果和ABAQUS计算结果进行比较,结果显示:优化结果不仅保持了钢板弹簧的计算精度,还可以提高钢板弹簧的计算效率。     

离合器碟形弹簧的优化设计

建立了离合器碟形弹簧的优化设计数学模型 ,应用约束度尺度优化方法 ,编制了离合器碟形弹簧的优化设计软件。利用该软件对SH5 0拖拉机主、副离合器碟形弹簧进行改进设计 ,结果表明优化设计可使离合器性能得到明显改善。     

基于遗传算法的弹簧的优化设计

采用一种现代的优化算法—遗传算法对弹簧进行优化设计 ,优化设计的结果证明遗传算法在弹簧的设计中同样有效。     

自调式膜片弹簧离合器优化设计

自调式膜片弹簧离合器在国外市场的广泛应用证明了它的优越性能.首先介绍了自调式膜片弹簧离合器的特点及其自调原理,创新的将优化设计方法引入了自调式膜片弹簧离合器的设计过程.广泛参考了传统膜片弹簧离合器和各种典型碟簧的优化设计方法,分别就基本参数、膜片弹簧和力感应弹簧三部分进行了优化设计.通过计算校核和有限元分析,证明该优化方法可行.     

基于可靠性的电磁振动器弹簧板组结构优化设计

对某电磁振动器中的弹簧板组结构进行基于疲劳可靠性的优化设计研究。考虑材料和几何尺寸的随机性 ,构建了以弹簧片数和弹簧板尺寸为设计变量 ,分别以弹簧板组总体积或弹簧板组总片数极小化为目标函数 ,同时满足弹簧板组系统的疲劳可靠度、弹簧板组的刚度和设计变量上下限约束的优化设计数学模型。分别对 4种设计方案进行了优化设计 ,获得了显著的效果     

任意分布参数的钢板弹簧的可靠性优化设计

在基本随机参数的前四阶矩已知的情况下,应用随机摄动法和Edgeworth级数方法对钢板弹簧进行可靠性优化设计,通过计算机程序可以实现随机参数服从非正态分布的钢板弹簧可靠性优化设计,迅速准确地得到了钢板弹簧的可靠性优化设计信息。     

一种基于行为建模技术的弹簧优化设计新方法

将基本结构参数作为弹簧的设计变量,优化目标为弹簧的最小质量,设计约束条件包括强度、刚度、稳定性等要求,建立了圆柱螺旋弹簧优化设计的模型.采用行为建模方法设置优化参数并建立分析特征,对机械弹簧进行优化设计,方便快速地获得了符合设计要求且质量最小的弹簧,为弹簧的优化设计提供了一种新的途径与方法.     

离合器碟形弹簧的优化设计

建立了离合器碟形弹簧的优化设计数学模型，应用约束度尺度优化方法，编制了离合器碟形弹簧的优化设计软件。利用该软件对ＳＨ５０拖拉机主、副离合器碟形弹簧进行改进设计，结果表明优化设计可使离合器性能得到明显改善。     

基于免疫遗传算法的离合器压紧弹簧优化设计及MATLAB实现

阐述了免疫遗传算法的基本原理,并在MATLAB环境下采用免疫遗传算法对离合器压紧弹簧进行了优化设计.实验表明免疫遗传算法对离合器压紧弹簧的优化设计效果明显.     

基于MatLab的圆柱螺旋压缩弹簧模糊可靠性优化设计

针对传统优化设计的局限性,通过应用模糊设计理论和可靠性设计理论,建立了圆柱螺旋压缩弹簧模糊可靠性优化设计的数学模型;给出了算例并采用MatLab对其进行优化。研究表明：模糊可靠性优化设计与MatLab相结合在弹簧的优化设计方面具有很好的应用效果。     

基于遗传算法的非线性控制系统参数优化方法

本文针对非线性控制系统参数优化问题,结合非线性控制系统理论、最优化理论及遗传算法,提出了一种新的仿真优化方法,该方法利用遗传算法来求解非线性控制系统参数优化问题,由于遗传算法是在解空间的多个区域内进行搜索,能以较大的概率跳出局部最优,因此可技巧以整体最优解。仿真结果表明,该方法是一种有效的非线性控制系统参数优化方法。     

Optimization of a structure with contact conditions using equivalent loads

Engineering structures consist of various components, and the components interact with each other through contact. Engineers tend to consider the interaction in analysis and design. Interactions of the components have nonlinearity because of the friction force and boundary conditions. Nonlinear analysis has been developed to accommodate the contact condition. However, structural optimization using nonlinear analysis is fairly expensive, and sensitivity information is difficult to calculate. Therefore, an efficient optimization method using nonlinear analysis is needed to consider the contact condition in design. Nonlinear Response Optimization using Equivalent Loads (NROEL) has been proposed for nonlinear response structural optimization. The method was originally developed for optimization problems considering geometric/material nonlinearities. The method is modified to consider the contact nonlinearity in this research. Equivalent loads are defined as the loads for linear analysis, which generate the same response field as that of nonlinear analysis. A nonlinear response optimization problem is converted to linear response optimization with equivalent loads. The modified NROEL is verified through three examples with contact conditions. Three structural examples using the finite element method are demonstrated. They are shape optimization with stress constraints, size optimization with stress/displacement constraints and topology optimization. Reasonable results are obtained in the optimization process.     

Machining process parameters optimization for heavy-duty CNC machine tools in sustainable manufacturing

Machining process parameters (MPP) directly affect the machining quality and efficiency of heavy-duty CNC machine tools (HCMT). The selection of MPP is very important to effectively improve machining performance. Machining performance has been closely related to the HCMT running state. In order to maintain HCMT sustainably manufacturing with high accuracy and low consumption after machining performance degradation for a long time running, MPP should be re-optimized according to the current state of the machine tools. Thus, this paper proposed a MPP optimization method for running HCMT to obtain optimal MPP based on current running state. A multi-objective optimization model was built, considering both the linear factors such as machining time and machining cost and nonlinear factors such as chatter in machining process. The nonlinear factors were reflected by the nonlinear dynamic model of machining process. Furthermore, a grid optimization algorithm was introduced to search the optimal MPP from the multi-objective optimization model. Finally, a case study was implemented to verify the feasibility of the nonlinear dynamic model and the superiority of the multi-objective optimization method compared with single-objective optimization method.     

Straightness and flatness tolerance evaluation: an optimization approach

This paper presents an optimization approach that could be used to calculate exact values of straightness and flatness errors as defined by the ANSI Y14.5M standards on geometric dimensioning and tolerancing. The straightness and flatness error evaluation problems are formulated as nonlinear optimization problems with linear objective function and nonlinear constraints. Because of the special structure of the problem, a linear search method is developed that reduces the nonlinear problem to a linear programming problem with only two constraints. Examples are presented to compare the optimization approach with the least-squares method and some exact methods. The results show that the optimization procedures presented in this paper provide exact values of straightness and flatness errors and are superior to the existing methods in terms of computation time.     

多目标优化设计在机构运动学综合中的应用

基于杆长约束,机构综合问题可以转化为非线性方程组的求解问题,再将非线性方程组转化为多目标无约束优化问题,应用多目标优化方法求解.应用多目标优化原理,首次提出了机构综合问题非线性方程组求解的新方法,并用Matlab语言的优化工具箱实现求解.机构运动学综合的实例表明该方法的正确性与有效性.     

基于粒子群优化的混合模型预测控制研究

为解决复杂非线性系统的控制精度不高,稳定性难于保证等问题、将预测控制技术应用于非线性控制中,提出了一种基于粒子群优化和混合模型的预测控制算法.混合模型预测控制算法使用模糊聚类和最小二乘法建立了系统的复合模犁,由带压缩因子的粒子群算法优化获得了非线性控制系统的控制量,在非线性模型上对模糊预测控制算法和混合模型预测控制算法...     

The structure optimization of tracked ambulance nonlinear vibration reduction system

Our aim was to improve the performance of tracked ambulance nonlinear vibration reduction system by structure optimization design. The structure optimization focuses on the stretcher base. Two structure optimization schemes are proposed based on the mechanism of Dynamic vibration absorber (DVA): Linear and nonlinear structure. The linear structure optimization scheme is finally adopted by comparison of the two schemes under random vibration, and the performance of linear scheme is also verified under shock vibration. Then the global sensitivity analysis method is applied to calculate the parameter sensitivity of nonlinear vibration reduction system. Finally, the Nondominated sorting genetic algorithm II (NSGA-II) is used to optimize the performance of the nonlinear vibration reduction system. It shows that the vibration energy of the supine human body on a stretcher is reduced after above studies, which proves the validity and feasibility of the structure optimization schemes proposed and the optimization studies applied in this paper.     

A new topology optimization scheme for nonlinear structures

A new topology optimization algorithm based on artificial bee colony algorithm (ABCA) was developed and applied to geometrically nonlinear structures. A finite element method and the Newton-Raphson technique were adopted for the nonlinear topology optimization. The distribution of material is expressed by the density of each element and a filter scheme was implemented to prevent a checkerboard pattern in the optimized layouts. In the application of ABCA for long structures or structures with small volume constraints, optimized topologies may be obtained differently for the same problem at each trial. The calculation speed is also very slow since topology optimization based on the roulette-wheel method requires many finite element analyses. To improve the calculation speed and stability of ABCA, a rank-based method was used. By optimizing several examples, it was verified that the developed topology scheme based on ABCA is very effective and applicable in geometrically nonlinear topology optimization problems.     

一种考虑参数相关性的可靠性优化设计方法

在求解具有非线性相关性结构的可靠性设计优化问题时,现有的相关性处理方法在某些情况下可能会得到精度较低的优化结果。基于Copula函数提出了一种可靠性优化设计方法,用于求解存在非线性相关性结构的可靠性优化设计问题。该方法根据已知的样本对各备选Copula函数进行参数估计,并根据AIC准则选出最优Copula函数。根据最优Copula函数,构建联合概率分布函数,最后求解结构可靠性优化设计问题。通过两个数值算例验证了该方法的有效性,并讨论了不同Copula函数对优化结果的影响。     

Optimization analysis of trajectory for re-entry vehicle using global orthogonal polynomial

We present a procedure for the application of global orthogonal polynomial into an atmospheric re-entry maneuvering problem. This trajectory optimization is imbedded in a family of canonically parameterized optimal control problem. The optimal control problem is transcribed to nonlinear programming via global orthogonal polynomial and is solved a sparse nonlinear optimization algorithm. We analyze the optimal trajectories with respect to the performance of re-entry maneuver.