抽油机典型结构件的设计与力学分析

结构强度是保证抽油机正常工作的基础，本文对抽油机结构件的典型结构进行了简要力学基础分析，为抽油机典型结构件设计提高了理论支持。     

基于CATIA的飞机结构件参数化设计

以CAA作为CAITA的二次开发工具,采用面向对象和可视化界面编程技术,针对飞机结构件开发出参数化设计系统,对特征模板进行交互式参数化设计,提高了对已有设计资源的利用率,实现飞机结构件的快速响应设计．     

基于接口仿真的雷达软件测试自动化技术研究与应用

嵌入式软件在雷达装备中发挥核心作用,采用传统的用户界面动态测试手段,难以实现充分的软件测试,易造成缺陷遗漏.本文针对基于接口仿真的软件测试技术展开研究,提出了适合于雷达软件的接口仿真自动化测试框架.同时针对雷达软件接口测试中,测试数据的结构建立与生成环节存在操作数据多、易出错、效率低等问题,以雷达软件接口定义头文件为输入,通过自动解析头文件结构体定义,为雷达软件接口仿真测试框架自动化建立通讯报文结构;总结定义了雷达软件接口测试数据设计的一般规则,并通过规则分析自动生化成测试数据,在有效提升雷达软件测试的覆盖率及缺陷检出率的基础之上,进一步提升了雷达软件接口测试的自动化程度.最后通过雷达软件测试典型项目的实例研究,验证雷达软件接口仿真测试自动化框架的效果.     

3D打印复杂点阵结构的缺陷三维可视化方法

针对3D打印的复杂点阵结构容易出现裂纹、未熔合或孔洞等缺陷,严重影响结构件的功能性能问题,开展了对3D打印的一种复杂点阵结构件的缺陷三维可视化检测方法研究。基于CT图像中结构件内部缺陷的灰度值差异特征,采用集合灰度值法自动识别一类缺陷并分割提取,由光线投射法对分割得到的缺陷序列图像进行三维重构。实验结果表明:所提方法有效获得了点阵结构件内部一种典型缺陷的三维可视图,从三维角度可对缺陷的形状、大小等形貌细节信息进行描述,为进一步分析缺陷对结构性能的影响提供了有力的依据。     

噪声雷达中频信号产生与基带接收系统

本文针对噪声雷达信号模型研究与实验的需求,基于高速FPGA、双通道高速DAC和双通道高速ADC芯片,开发了噪声雷达中频信号产生与基带接收系统.该系统的最大发射和接收信号带宽分别为220 MHz和200 MHz,可作为研究噪声雷达信号模型和处理算法的实验平台.介绍了系统的软硬件设计,给出了Chirp信号和混沌噪声信号的产生与接收采样以及处理结果,验证了设计的正确性和所开发平台的可用性.     

软模辅助RTM成型舱段构件及其性能研究

某些复合材料结构件尺寸较大且内部结构复杂,难以通过传统RTM工艺一次整体成型,并且因其成型压力低而致纤维含量不高,成型构件力学性能不佳.本研究用硅橡胶来浇铸成型特定形状的软模,采用软模辅助RTM来制备舱段构件这一典型航天结构件.由于硅橡胶软模在复合材料固化成型过程中发挥了设计中的膨胀挤胶作用,复合材料的纤维体积含量和力学性能得到了显著提高,舱段整体力学性能满足了航天主承力结构件的使用要求,因此软模辅助RTM在制备具有内部复杂结构的装备结构件上具有广阔的发展前途.     

光纤传感系统应用于FRP混凝土结构振动检测的实验研究

本文引入基于马赫—曾德(Mech-Zehnder)干涉原理的光纤传感振动检测系统,成功地进行了FRP混凝土结构的振动检测。光纤传感器粘贴于结构件表面(或埋入结构件内部)的干涉型光纤技术,为复合材料结构的实时振动监测提供了一个新方法。     

用ⅤⅪ仪器组建通用雷达装备自动测试系统

雷达武器装备的发展对测试系统提出了越来越高的要求.本文介绍了基于ⅤⅪ总线卡式仪器和GPIB仪器组建的通用雷达装备自动测试系统的硬件结构,说明了测试软件的体系结构和设计方法.应用实践表明系统具有自动化程度高、通用性强、测试速度快、故障检测率高和操作使用简单等特点,具有较高的工程实用价值及推广价值.     

可变功能机械行为链序结构相似性及应用

为研究以可变功能为目标的机械系统再设计,行为过程作为产品设计理论研究的一个重要方面,为设计者提供了较大的创新空间.基于系统相似性,通过对典型可变功能机械各行为过程进行行为链的序结构相似性分析,总结了可变功能机械各对应行为链序结构具有功能有序、结构有序及运动时间有序的特点及规律,归纳出基于行为链序结构相似性的应用性规则,提出运用行为链序结构的相似性及其变化特点为系统进行可变功能再设计及优化提供新的理论与方法.最后,用实例验证了结论的正确性及可行性.     

基于HLA的火控雷达网融合控制系统仿真研究

为提高火控雷达的战场生存能力,研究通过组网技术降低雷达信号截获概率的方法。根据设定作战场景,介绍火控雷达网的工作过程,给出融合控制系统的结构及动态执行过程,设计基于高层体系结构的火控雷达网融合控制系统仿真软件,以此作为平台验证火控雷达组网理论的正确性。最后,通过RTI平台进行仿真实验,结果表明:仿真系统可以有效模拟火控雷达网的数据融合处理和雷达参数控制,组网系统能够延长火控雷达被敌方侦察系统的截获时间。     

An expert system for the design and analysis of composite structures

A prototype expert system is described for concurrent design and analysis of composite structures. This system integrates symbolic, numerical and knowledge-based tools in an object-oriented programming environment for design synthesis, evaluation and modification. The system determines structural behavior utilizing a combination of analytical and numerical tools. Design modifications and structural optimization are performed using heuristic and experientially derived knowledge bases. The different domain-specific programs and commercial packages utilized by the system are integrated using a generic interfacing mechanism. The utility of the system is demonstrated by means of a design case study for a typical aircraft or rotorcraft structural component.     

基于复合仿真技术的武器装备工业造型设计方法

目的 将仿真技术作为武器装备工业造型设计中的重要手段,使国防武器装备在满足隐身性能和结构强度的要求下,提升装备工业造型的视觉气质.方法 首先依据隐身理论提出武器装备造型的隐身设计策略,然后利用隐身仿真技术与有限元仿真技术对武器装备工业造型方案进行隐身性分析、静力学分析、动力学分析以选出最优设计方案,并找到方案中的结构薄弱部位,最后通过结构优化方法对其薄弱部位进行造型优化设计.结论 以舰载雷达天线座为例验证了基于隐身分析与有限元分析的工业造型设计方法可应用在武器装备领域.     

VARI工艺制备典型平面及曲面构件的流道设计模拟研究

对典型平面及典型曲面构件进行了VARI工艺模拟分析,分别采用不同的模拟方案对两类构件进行流道设计模拟研究,由此得出了两类构件工艺流道设计的异同点,旨在针对不同构件的结构特点,选择最佳的注射方式及合理的流道设计方案,从而为模具设计及构件制造提供重要依据。     

Automated manufacturability evaluation system for sheet metal components in mass production

Automated manufacturability evaluation of a given design is a key requirement in realizing complete integration of design and process planning. It would still be better to control the designing process itself with manufacturability information. The purpose of such an evaluation is to assist designers in their effort to come up with manufacturable parts economizing in terms of cost and time, without compromising on quality and functional requirements. The present work deals with one such system developed for manufacturability evaluation of sheet metal components. Unlike most of the work done in the sheet metal area in the past, which concentrates on specific domain or phase of manufacturability evaluation, the present work is more comprehensive combining characteristics of all the existing methods and phases of manufacturability evaluation. The prime components of the present system are design evaluation and process plan generation. Design evaluator and process planner use different types of data and knowledge to identify design and process planning violations which are overcome by suggesting design changes. A process planner also uses manufacturing resource and process information to arrive at manufacturable parts by generating feasible process plans. Results of manufacturability evaluation are presented for typical sheet metal parts to be produced by bending and shearing (blanking and piercing) processes.     

An Expert System in FRP Composite Material Design

An expert system prototype for fibre-reinforced plastic matrix (FRP) composite material design, ESFRP, has been developed. The system consists of seven main functional parts: a general inference engine, a set of knowledge bases, a material properties algorithm base, an explanation engine, various data bases, several function models and the user interface. The ESFRP can simulate human experts to make design scheme for fibre-reinforced plastics design, FRP layered plates design and FRP typical engineering components design. It can also predict the material properties and make strength analysis according to the micro and macro mechanics of composite materials. A satisfied result can be gained through the reiterative design.     

Simple methods of determining stress intensity factors

A prerequisite for any fracture mechanics analysis of a cracked structure, is a knowledge of the stress intensity factor at the tip of the crack. Many methods are available for evaluating stress intensity factors, but if the structural configuration is complex, they are usually costly in time and money. This paper describes some simpler approximate methods which are both quick and cheap. Their use is illustrated by examples typical of aerospace applications, e.g. cracks at holes and cracks in stiffened sheets. The errors introduced into calculations of residual static strength and fatique lifetimes by the use of such approximations are acceptable for many practical cases: They are usually no greater and often smaller than those due to uncertainties in other parameters such as service loads, material toughness, etc.     

面向CAD/CAPP集成的零件信息描述方法的研究

零件信息的描述及其数据的处理是实现CAD/CAPP集成的关键.文中论述基于特征的零件信息描述方法,对于回转体零件以形体特征描述为主导,对于箱体零件以基于零件典型实例的特征形面描述为依据,从而为实现CAD与CAPP的顺利集成奠定基础.在分析基于实例和特征的零件信息描述方法的基础上,结合具体的应用系统阐明该方法的应用过程.     

雷达射频测试系统现场整体计量校准技术研究

传统的集成系统校准是采用单台仪器计量和系统功能检查来完成,原有的系统性能和技术指标是无法保证的,雷达射频测试系统的整体校准是目前急需解决的问题。本文通过设计组配标准化、通用化的现场传递标准件,即通过组配单件传递标准件、组合传递标准件,建立了与雷达射频测试系统相对应的功率、幅度、相位、噪声和反射系数等电参数的工作标准,通过对以上各参数的不确定度分析评定和重复性、稳定性的考核,解决了雷达射频测试系统的量值传递问题,实现了雷达射频测试系统的现场整体校准。     

Life cycle monitoring and advanced quality assurance of L-shaped composite corner part using embedded fiber-optic sensor

L-shaped composite parts are structural key elements in complex-shaped aerospace composite structures, and life cycle cross-sectional strain change is their key. This study developed a fiber-optic-based life cycle monitoring system for L-shaped corner parts. A fiber Bragg grating (FBG) sensor was embedded in the through-thickness center of a corner part and the cross-sectional strain change was continuously evaluated by using a birefringence effect of the FBG. The embedded sensor could capture key strain changes throughout the structural life cycle, confirming that “non-axisymmetric strain” of the FBG sensor is a good indicator for spring-in distortion in manufacturing and through-thickness tensile failure in operation. The developed system was further utilized for advanced quality assurance of assembled L-shaped parts, and a new strength prediction method was proposed based on the FBG response. The monitoring system developed can provide a deep insight about the current internal state of L-shaped parts, and the information obtained is highly valuable for improving the design/manufacturing and for diagnosing the structural health.