飞机登机门门区结构设计及优化

优化设计可以改善结构的应力分布,合理布置材料,从而提高材料的利用率.在完成飞机登机门门区结构的初步设计后,通过对登机门门区结构逐层分解,确定优化设计变量、优化区域以及响应约束,并应用MSC Nastran进行优化,初步确定登机门门区结构尺寸.     

基于优化设计的单元尺寸确定方法

利用ANSYS软件对结构进行有限元仿真时，单元尺寸对仿真结果具有重要影响。分别以单元尺寸0．008m、0．002m对悬臂梁进行仿真分析，结果表明不合适的单元尺寸会导致错误的仿真结果；介绍了ANSYS软件的优化设计；提出了一种采用优化设计确定单元尺寸的新方法；解决了单元尺寸不易确定的问题。     

基于准则法的飞机薄壁结构可靠性优化设计

针对传统的安全因数法考虑载荷和强度不确定性因素对飞机安全性的影响太笼统,无法从根本上减轻飞机结构质量的问题,提出一种飞机结构可靠性优化设计方法.根据应力-强度干涉模型计算结构单元的可靠度,建立以单元满可靠度为准则的优化模型,实现包含可靠性约束的结构尺寸优化.该功能已经加入到COMPASS中.算例结果表明该方法能够减轻结构质量,改善结构可靠度.该方法为开展飞机结构不确定性设计提供技术手段.     

卫星结构板优化设计

利用MSC Patran对某板式卫星结构进行有限元建模,采用MSC Nastran对卫星进行模态分析,获取整星结构的模态参数,并与试验结果进行比对,验证有限元模型的正确性和准确度。在满足结构强度和刚度的约束条件下,对安装有效载荷单机的关键底板进行刚度和强度优化设计。优化前后结构的有限元仿真分析表明：优化设计可有效抑制载荷单机处的振动位移响应。     

高性能计算在多学科大变量飞机优化设计中的应用

波音、空客等公司飞机设计中采用的先进设计手段之一是基于高性能计算的多学科、大规模设计变量优化的应用。目前我国的高性能计算在硬件方面已处于世界领先水平,但在工程应用系统方面还无法满足需求。文章介绍了以工程实际需求为导向,以高性能计算资源为辅助手段,基于飞机设计需求而开发的多学科、大变量的并行计算软件系统及计算平台,以及利用该平台实现的航空应用算例。     

CPU散热片结构优化设计

本文运用APDL(AnsysParameterDesignLanguage)语言,在ANSYS开发环境中对平板式散热片进行结构优化设计,并给出实例验证本文提出的方法。     

交通标志结构的有限元优化设计

交通标志的结构设计采用有限元分析法进行优化设计,能够让交通标志结构的稳定性更加符合交通安全性要求,同时使结构外观和公路环境相协调。本文对常规有限元法和精确有限元法在设计交通标志牌结构时做了对比分析,阐明了精确有限元法在结构设计上更具有优势。     

遥控武器站结构优化设计

根据第四强度理论和模态分析理论,对遥控武器站系统进行静力学分析和模态分析。分析托架在武器发射载荷下的应力和应变值,根据分析结果对其结构进行优化设计,优化设计后托架质量减轻54%,转动惯量减小51%。对系统整体结构进行模态分析,系统一阶模态频率为156.71Hz,远远大于武器系统的工作频率,系统在武器发射时不会发生共振。     

冲击载荷下磁流变阻尼器结构优化设计

应用于火炮反后坐装置中的磁流变阻尼器工作在高冲击、高速环境下,对磁流变阻尼器的设计指标和性能提出了更高的要求.针对冲击试验中,磁流变阻尼器表现出的阻尼力可调动态范闱的不足,利用Herschel-Bulkley的磁流变液非线性结构特性的平行平板恒流模型,采用多目标规划方法,提出了火炮反后坐装置应用中的磁流变阻尼器优化设计方法.最后分析了磁流变阻尼器磁路设计准则,结合优化设计尺寸,对阻尼器活塞磁场进行了有限元分析.结果表明,磁流变阻尼器阻尼通道处能产生足够大的磁场强度且分布均匀.     

利用UG有限元优化设计机械结构

某企业在其石油机械产品关键部件设计开发中,使用常规手段进行强度计算,该部件在使用过程中发生失效断裂的情况,为此,他们委托新疆科力先进制造技术有限责任公司对该部件设计方案进行有限元静力分析,来验证其设计方案是否合理,并希望得到该部件优化设计的改进依据.     

Reliability-based topology optimization

The objective of this work is to integrate reliability analysis into topology optimization problems. The new model, in which we introduce reliability constraints into a deterministic topology optimization formulation, is called Reliability-Based Topology Optimization (RBTO). Several applications show the importance of this integration. The application of the RBTO model gives a different topology relative to deterministic topology optimization. We also find that the RBTO model yields structures that are more reliable than those produced by deterministic topology optimization (for the same weight).     

Integration of topology and shape optimization for design of structural components

This paper presents an integrated approach that supports the topology optimization and CAD-based shape optimization. The main contribution of the paper is using the geometric reconstruction technique that is mathematically sound and error bounded for creating solid models of the topologically optimized structures with smooth geometric boundary. This geometric reconstruction method extends the integration to 3-D applications. In addition, commercial Computer-Aided Design (CAD), finite element analysis (FEA), optimization, and application software tools are incorporated to support the integrated optimization process. The integration is carried out by first converting the geometry of the topologically optimized structure into smooth and parametric B-spline curves and surfaces. The B-spline curves and surfaces are then imported into a parametric CAD environment to build solid models of the structure. The control point movements of the B-spline curves or surfaces are defined as design variables for shape optimization, in which CAD-based design velocity field computations, design sensitivity analysis (DSA), and nonlinear programming are performed. Both 2-D plane stress and 3-D solid examples are presented to demonstrate the proposed approach. Received January 27, 2000 Communicated by J. Sobieski     

Order-(n+m) direct differentiation determination of design sensitivity for constrained multibody dynamic systems

With the complexity and large dimensionality of many modern multibody dynamic applications, the efficiency of the sensitivity evaluation methods used can greatly impact the overall computation cost and as such can greatly limit the usefulness of the sensitivity information. Most current direct differentiation approaches suffer from prohibitive computational cost, which may be as great as O(n⁴+n²m²+nm³) (for systems with n generalized coordinates and m algebraic constraints). This paper presents a concise and computationally efficient sensitivity analysis scheme to facilitate such sensitivity calculations. A unique feature of this scheme is its use of recursive procedures to directly embed the algebraic constraint relations in forming and simultaneously solving a minimal set of equations. This results in far fewer operations than more traditional, or so-called O(n), counterparts. The algorithm determines the derivatives of generalized accelerations in O(n+m) operations overall. The resulting equations are exact to integration accuracy and enforce constraints exactly at both the velocity and acceleration levels.     

基于随机灵敏度分析的化工过程裕量设计

对化工过程进行最优设计时,由于过程中参数的不确定性,需要在既满足过程约束又保证经济效益最优的前提下对设计变量增加裕量。本文考虑过程不确定参数的随机分布,结合灵敏度分析,提出一种基于随机灵敏度的化工过程最优裕量设计方法。首先,取不确定参数的标称值,进行化工过程最优设计,得到最优设计点的标称值;其次,假设过程不确定参数服从正态分布,基于灵敏度分析确定约束变量的均值和方差,在保证低概率违反约束的条件下优化求解设计裕量,定量分析不确定参数对设计变量的影响;最后,通过对串联连续搅拌釜式反应器（Continuous stirred tank reactor,CSTR）系统进行仿真实验,说明该裕量设计方法的具体步骤,并得到合理的设计裕量值,验证所提方法的正确性。     

基于MOLCA的催化裂化分离系统多目标模糊优化

催化裂化分离系统由分馏系统和吸收稳定系统两部分组成,本文将催化裂化分离系统作为一个整体进行研究。应用流程模拟软件Aspen Plus建立了该系统的全流程模拟,在此基础上,以干气中C_（3＋）组分数最小和系统能耗最少作为优化目标,建立了该系统的多目标优化数学模型。应用模糊优化理论对优化约束条件进行模糊处理,并采用多目标列队竞争算法（MOLCA）对模糊优化模型以及普通优化模型进行求解。计算结果表明,采用模糊优化的结果优于普通优化的结果,干气品质和系统能耗都得到了明显的改善。为催化裂化分离系统的操作优化提供了参考。     

基于Adams/Car的汽车前悬架仿真分析及优化设计

针对某车型的麦弗逊前悬架系统,用车辆多体动力学仿真软件Adams/Car建立该悬架的虚拟样机模型,对其进行双轮同向跳动激振仿真分析,并综合评价该悬架的车轮定位参数、主销后倾拖距和转向角随轮跳的响应特性.在仿真分析的基础上,针对不合理的结构设计参数,利用Adams/Insight模块进行基于设计变量灵敏度分析的优化设计.优化后的悬架参数能很好地满足设计要求,从而达到提高该悬架系统整体性能的目的.     

Shape design optimization of stationary fluid-structure interaction problems with large displacements and turbulence

This paper presents general and efficient methods for analysis and gradient based shape optimization of systems characterized as strongly coupled stationary fluid-structure interaction (FSI) problems. The incompressible fluid flow can be laminar or turbulent and is described using the Reynolds-averaged Navier-Stokes equations (RANS) together with the algebraic Baldwin–Lomax turbulence model. The structure may exhibit large displacements due to the interaction with the fluid domain, resulting in geometrically nonlinear structural behaviour and nonlinear interface coupling conditions. The problem is discretized using Galerkin and Streamline-Upwind/Petrov–Galerkin finite element methods, and the resulting nonlinear equations are solved using Newtons method. Due to the large displacements of the structure, an efficient update algorithm for the fluid mesh must be applied, leading to the use of an approximate Jacobian matrix in the solution routine. Expressions for Design Sensitivity Analysis (DSA) are derived using the direct differentiation approach, and the use of an inexact Jacobian matrix in the analysis leads to an iterative but very efficient scheme for DSA. The potential of gradient based shape optimization of fluid flow and FSI problems is illustrated by several examples.