Multidisciplinary design optimization based on independent subspaces

Optimization has been successfully applied to systems with a single discipline. Since many disciplines are involved in a coupled fashion in modern engineering, multidisciplinary design optimization (MDO) technology has been developed. MDO algorithms are designed to solve the coupled aspects generated from the interdisciplinary relationship. In a general MDO algorithm, a large design problem is decomposed into smaller ones which can be easily solved. Although various methods have been proposed for MDO, research is still in the early stage. This study proposes a new MDO method which is named MDO based on independent subspaces (MDOIS). Many real engineering problems consist of physically separate components and they can be independently designed. The inter‐relationship occurs through coupled physics. MDOIS is developed for such problems. In MDOIS, a large system is decomposed into small subsystems. The coupled aspects are solved via system analysis which solves the coupled physics. The algorithm is mathematically validated by showing that the solution satisfies the Karush–Kuhn–Tucker condition. Copyright © 2005 John Wiley & Sons, Ltd.     

A review of modeling approaches for oriented semi-crystalline polymers

Modeling changes in the physical properties of oriented semi-crystalline polymer films is beneficial for understanding the fundamentals associated with structure property relationships and could be used for developing new polymer films with significantly enhanced physical properties. Relating the molecular changes observed in oriented polymer films to inherent polymer characteristics provides valuable insight for the development of new polymers which exhibit enhanced physical properties upon orientation. Modeling efforts will be reviewed that have attempted to use fiber composite theory to explain the transitions seen during the orientation process.     

Ram‐air kite airfoil and reinforcements optimization for airborne wind energy applications

We present a multidisciplinary design optimization method for the profile and structural reinforcement layout of a ram‐air kite rib. The aim is to minimize the structural elastic energy and to maximize the traction power of a ram‐air kite used for airborne wind energy generation. Because of the large deformations occurring during flight, a fluid‐structure interaction (FSI) routine is included in the optimization, which determines the actual deformed rib geometry and its corresponding aerodynamic characteristics. A qualitative comparison between FSI inclusion and exclusion in the optimization is given. Discrepancies in airfoil profile and structural layout are observed.     

基于iSIGHT的单学科设计优化与多学科设计优化的比较

研究了单学科设计优化技术和多学科设计优化技术,在iSIGHT和Ansys软件集成环境下,对CellPhone进行优化.单学科设计优化平台和多学科设计优化平台得出的优化结果进行了比对,验证了多学科设计优化平台的先进性和全面性.     

基于MDO方法的车用三效催化转化器设计优化

以车用三效催化转化器（TWC）的转化效率、压力损失、质量以及抗热冲击性能为目标函数,建立了TWC多学科设计优化（MDO）模型。在充分考虑各学科之间的耦合效应基础上,通过采用自适应混沌优化算法与VB编程对MDO模型进行求解。优化结果表明,压力损失减少699%,质量减少1168%,位移变形减少2091%,TWC转化效率提高542%。试验证明该方法用于TWC是有效的。     

飞行器可靠性与性能一体化设计初步研究

飞行器可靠性设计与性能设计的分离制约了飞行器设计水平的提高。文中介绍了一体化设计的概念和发展情况,提出了可靠性与性能一体化设计的技术理论,并对其进行三维空间内的分析,给出了实现的概要方法。     

MDO中基于标准数据交换的多学科软件集成研究

多学科软件集成是实现MDO的基础,针对设计分析软件的不同类型特点,提出了以标准数据交换实现多学科软件集成的方式,分析了常用标准数据交换格式和基于标准数据交换格式的MDO结构,实现了基于UG二次开发的标准数据交换的多学科软件集成接口,并以简单机翼设计的CAD-气动分析为例对接口进行了验证.     

Structure Design of Turbo-Jet Engine Blade with Feature Based Parametric Modeling

1 Introduction Aeroengine turbine blade, working in high temperature, high pressure and high speed conditions, is the key part of gas turbine engine. Structure design of turbine blade is very complicated because not only the geometric elements, such as the shape of exterior and interior surfaces, allocation of lots of features’ and their orientation affected its performance, but also the multidisciplinary design process, including aerodynamics, heat transfer, strength, vibration, etc. as show…     

Optimal rapid multidisciplinary response networks: RAPIDDISK

The role of uncertainty in information rich design systems is critical to the development of advanced propulsion systems. Future turbine engines would have lower lifetime operating costs similar to current evolving automotive systems. Detailed multi-physics models (thermo-fluid, structural and mechanical systems) and an operational environment are enablers of rapid correction and model-based predictive analyses. Bayesian machine learning paradigms are developed to identify the behavior of turbo-machinery components for preliminary design. The embedded models approach enables systematic evolution from individual components level to the advanced engine. The embedded models approach enables systematic evolution from individual components level to the advanced engine. A rapid response strategy is proposed, for design of turbine disks by using multidisciplinary optimization and neural networks. iSIGHT optimization software is interfaced with ANSYS to find optimum designs for a given set of design boundary conditions (rpm, live rim load, thermals, etc.). The optimum designs obtained from iSIGHT for different set of design conditions are used for machine learning and design knowledge recognition using the neural network technique. The trained network is used to predict responses for design boundary conditions. Responses predicted by the neural network are validated using ANSYS. Discrete design points are chosen from the wide design space of turbine disks. A hierarchical neural network approach provides an ability to quickly train the network and predict responses (weight, stresses, burst margin, etc.) for applied design conditions. This basic building process involves four steps starting from identifying design boundary conditions to the prediction of design shape for the disk. Sensitivity-based scaling rules are developed, to accommodate different materials for the disk. The technique is developed in RAPIDDISK, which provides an optimal preliminary shape and design attributes for a turbine disk.     

BLISS方法的基本理论及应用

在分析、研究BLISS方法理论的基础上，提出了针对BLISS方法的一般性系统分解准则及其子系统的目标函数的确定方法，并结合齿轮减速器的算例证明了该方法的可行性和有效性。该方法可以作为BLISS方法在实际应用中的补充和完善。