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.     

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。     

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。     

消力池优化设计专家系统总体框架构建与研究

本文主要讨论了消力池优化设计专家系统的总体设计。根据消力池的具体特点，知识规则的表示方法和推理机的推理方法的设计均采用面向对象技术。系统主要是以数据库、知识库、模型库为数据源，利用推理机推理出最优消力池。另外，系统有机集成了人工智能技术、图像处理技术、仿真技术、数据库技术、模式识别技术等先进技术。     

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。     

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。     

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。     

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.     

面向分级设计优化的飞行器参数化建模方法

针对飞行器气动隐身外形综合设计优化问题,提出合适的面向分级设计优化流程,建立适应该流程的渐进分层参数化建模方法;用基于敏度分析的参数影响程度分析方法筛选复杂设计变量;采用多学科设计优化（Multidisplinary Design Optimization,MDO）理论和差分进化算法进行飞行器气动隐身外形的综合设计优化.将该方法用于某飞行器外形设计优化,结果表明：该方法合理可行,可为飞行器外形多学科设计优化提供一定参考.     

新涡桨飞机机头结构优化设计

在新涡桨支线飞机机头结构初始方案设计阶段,采用MSC Nastran对机头初始设计方案进行总体结构分析和尺寸优化,为机头结构选型和详细设计提供参考.     

飞机结构整体优化和细节分析

飞机结构复杂,部件众多,连接形式复杂,传统的单一计算方法已很难满足计算要求,为更好地挖掘飞机的承载能力,还要考虑结构局部进入塑性区应力分布.对飞机结构进行有限元分析,有时需同时考虑整体和局部,大型结构采用较密的网格会耗费大量时间、资源等,甚至会导致计算不收敛;局部结构须划分较细的网格才能得到局部构件的细节应力.以某型飞机机翼为例,简单介绍开展飞机结构整体优化和细节分析的方法与流程.     

Application of multiobjective optimization in aircraft control systems design

Multiobjective optimization techniques are applied in the design of an aircraft lateral control system. A large manned reentry vehicle and a fighter aircraft are considered. An algorithm suggested by Lin's Proper Inequality Constraints method, is implemented in the numerical computation of Pareto-optimal solutions. Subsequently, a trade-off analysis of several Pareto-optimal solutions is conducted.     

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     

基于多模型拓扑优化方法的车身结构概念设计

为获得最优的初始设计方案,在车身概念设计阶段对车身结构进行拓扑优化。车身结构性能指标综合考虑整体刚度、局部动态刚度和碰撞性能,采用多模型优化(multi-model optimization,MMO)方法解决此类复杂工况的拓扑优化问题,通过调节设计空间和设置参数,获得车身最优载荷路径。根据拓扑优化结果初步形成车身框架结构,可为后期详细设计提供参考。     

Extension of optimum safety factor method to nonlinear reliability-based design optimization

In the reliability-based design optimization (RBDO) model, the mean values of uncertain system variables are usually applied as design variables, and the cost is optimized subject to prescribed probabilistic constraints as defined by a nonlinear mathematical programming problem. Therefore, a RBDO solution that reduces the structural weight in uncritical regions does not only provide an improved design but also a higher level of confidence in the design. In this paper, we present recent developments for the RBDO model relative to two points of view: reliability and optimization. Next, we develop several distributions for the hybrid method and the optimum safety factor methods (linear and nonlinear RBDO). Finally, we demonstrate the efficiency of our safety factor approach extended to nonlinear RBDO with application to a tri-material structure.     

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.