加强飞机战斗损伤容限的飞机设计一体化研究

为了提高未来军用飞机的作战效率,在设计的早期就要考虑到飞机的战斗损伤容限而对飞机进行一体化设计。论文讨论了飞机战斗生存力的设计要求,具有战斗损伤容限和具有很强生存能力飞机的设计方法。     

三维损伤容限设计:离面约束理论与疲劳断裂准则

损伤容限设计是为保证含裂纹结构安全而发展的抗疲劳断裂设计方法.其核心思想是:承认构件中存在初始裂纹,基于断裂力学理论对裂纹疲劳扩展寿命和结构剩余强度进行分析和试验验证,并结合定期检查,保证结构在服役中裂纹不会发生失稳扩展.对于承受交变载荷的结构,如飞机、轮船、压力容器等,损伤容限设计思想已成为保证大型装备服役安全性和经济性相统一的科学设计理念.在回顾飞机结构强度设计理念发展的基础上,总结了损伤容限设计思想的科学内涵;阐明了损伤容限设计的理论基础—断裂力学—由二维理论发展到三维理论的必要性;详细介绍了三维损伤容限设计的理论、方法与应用.最后,对损伤容限设计的进一步发展作了简要展望.     

基于实测数据的飞-续-飞疲劳载荷谱研究

长寿命、高可靠性和低维修成本的综合要求,已成为飞机设计的重要准则.结构疲劳与损伤容限设计是满足上述要求的重要设计原则与方法,其中通过疲劳设计保证飞机的经济性,通过损伤容限设计保证飞机的安全性.为了满足飞机疲劳强度设计要求,应开展飞机结构疲劳寿命评定.若应力水平增大10％,可使飞机的疲劳寿命降低42％,可见应力水平对疲劳...     

基于概率损伤容限设计的飞机与发动机结构可靠性研究

从概率断裂力学与概率损伤容限分析的关系出发，确定了能够应用概率损伤容限设计的飞机与发动机疲劳关键结构，给出了应用概率断裂力学得出的从初始裂纹到临界裂纹疲劳循环总数计算公式。     

基于NASGRO飞机典型结构裂纹扩展分析

损伤容限评定已经成为当前民用飞机设计的指令性要求,裂纹扩展分析是损伤容限评定的重要手段之一。NASGRO作为专业软件,提供了计算平台,根据不同的裂纹扩展分析模型,对飞机典型结构(机身加强框、机翼下壁板)进行裂纹扩展计算,比较不同方法对结果的影响。     

基于损伤容限的整体梁多目标优化设计方法研究

针对整体结构的传统设计方法不能保证其在整个设计使用寿命中安全性和经济性的问题,着重研究了整体结构损伤容限设计方法。以飞机整体梁结构为例,建立了以结构截面参数为设计变量,结构重量和剩余强度综合最优为优化目标的优化模型,通过遗传算法,得到了不同权重系数下的优化结果。所用方法可为整体梁结构损伤容限设计提供了指导与参考。     

复合材料结构修理容限的确定

从工程应用的角度探讨了进行复合材料飞机结构损伤修理容限需要进行研究的相关问题,针对普通层压板和加筋板等结构的主要损伤形式,提出了针对修理容限问题较为系统的总体研究方案。结合结构的具体损伤形式指出了修理容限研究中需要进行理论分析和试验研究的内容,为不同材料同类结构修理容限的研究提供参考。     

浅谈飞机复合材料的修理

本文以飞机复合材料结构为主要研究对象,从复合材料结构的设计原则、复合材料的损伤分类、修理区域的划分及修理容限的规定、修理方法的分类等方面对飞机复合材料的修理进行了总结和概括。     

飞机整体梁结构止裂筋条结构参数确定方法

介绍了组合翼梁和整体翼梁结构的区别,利用ANSYS软件对整体翼梁损伤容限特性进行分析,讨论了有止裂筋条和无止裂筋条两种情况下的损伤容限特性,研究了止裂筋条在不同结构参数面积下的应力强度因子变化规律。根据静强度理论、断裂力学准则及检查间隔要求,结合整体翼梁结构参数及其传力特点,在止裂筋条面积赋初值的基础上,从止裂筋条面积能否同时满足静强度理论、断裂韧性准则及检查间隔要求角度,采用计算迭代给出了飞机整体翼梁止裂筋条结构参数确定方法。为今后飞机整体翼梁结构损伤容限设计提供了参考依据。     

民机结构疲劳损伤可靠性分析

为不断改进飞机结构设计提供技术支持,在飞机结构设计和维修中,需制订一套实用的结构疲劳分析程序,以便于结构工程师确定出合理的检查任务,以此来保证结构疲劳可靠性。结构疲劳的可靠性是通过设计阶段的疲劳设计和疲劳损伤觉察可靠性评估来保证。疲劳设计是采用"分散因子"的方法来确定结构疲劳可靠性。针对飞机维修和修理过程中遇到的疲劳问题,对结构疲劳评估和损伤容限评估进行了研究和分析。     

飞机战伤抢修性设计探析

面对未来战场的需要,开展飞机战伤抢修性设计研究具有非常深远的意义.介绍了飞机战伤抢修性的概念及其特征,提出了一套比较系统、全面的飞机战伤抢修性设计总原则和设计准则的理论体系,为飞机战伤抢修性设计提供一定的理论参考依据.     

飞机总体设计评价准则和评估方法研究

飞机总体设计评价是飞机研制过程的关键环节。基于军机的可支付性、任务性能、安全性、生存力、可用性(战备状态)等性能标准,考虑用户要求和上述指标对飞机系统的综合影响,建立了飞机总体设计综合评价准则。给出了每项指标的具体量度和评价准则计算公式以及分析了飞机总体设计的评估方法。     

Numerical study on determining design parameters of wheeled armored vehicles

The survivability of the crew is the most important factor to be considered when designing the body of a military combat vehicle, and the design must protect against armor-piercing projectiles and mine blasts, in order to enhance survivability. In this paper, we propose a numerical approach that can be used in the initial design stage when designing military combat vehicles that provide adequate protection against ballistics and mines. First, the basic shape of the vehicle is defined based on an analysis of the dimensions of a similar vehicle, and the thicknesses of the front and side plates are determined by performing a ballistic impact simulation. For the bottom plate design, the primary design parameters and their values, such as the stand-off, bottom angle, bottom thickness, and bottom-side thickness, are defined. Next, the results of a main effect analysis and an analysis of variance for each design parameter are compared to the response indices representing the performance of the vehicle as determined based on the results of the blast impact simulation and then main effect parameters for each response index are confirmed. In addition, the suitable shapes and dimensions of the vehicle that can meet the armor-piercing projectiles and mine blast threat conditions and design constraints are determined from the blast impact simulation results of the design models determined by the design of experiments method.

     

Failure behavior of a composite T-joint subjected to hydrodynamic ram

The Hydrodynamic ram (HRAM) phenomenon is one of the main types of ballistic battle damages of a military aircraft and has great importance to airframe survivability design. The HRAM phenomenon occurs in aircraft wing structures with internal fuel tanks. HRAM can generate approximately 690 bar (10000 psi) of pressure in the fuel tank. It causes significant damage to the wing fuel tank, which contains the fluid, and the connection structure of the wing fuel tank. The HRAM effect occurs due to the interaction between the fluid and structure, and damage can be investigated by measuring the pressure of the fluid and the dynamic strains on the structure. In this paper, a static test and an HRAM test of a composite T-joint were performed. The HRAM test utilized a ram simulator which can generate HRAM pressure. When a high speed cylindrical puck was fired to the ram simulator filled with water, HRAM pressure was generated, and the pressures of the fluid was measured. The failure behavior of the composite T-joint due to HRAM pressure was examined using the strain gauges and a PVDF sensor which were attached to the surface of the composite T-joint.     

飞机系统抢修性量化模型

面对未来战场的需要,开展飞机系统抢修性定量研究具有非常深远的意义。介绍飞机系统抢修性的概念,建立抢修性函数,推导并构建飞机系统抢修性参数量化模型。应用上述量化模型进行实例分析,结果表明:该量化模型具有很好的可行性和有效性,能对抢修性参数进行合理度量,较好地解决了飞机系统抢修性的度量难题。     

Requirements for safe operation of transport aircraft structures

The paper presents recommended criteria of operational survivability of structures at the aircraft design stage. The criteria are based on a generalization of results of computational and experimental studies conducted in the TsAGI with companies O.K. Antonov, S.V. Il’yushin, A.N. Tupolev, and A.S. Yakovlev, taking into account foreign experience. Requirements for determining intervals between inspections to detect corrosion and fatigue damage are considered.     

离散源撞击下结构生存力研究中的若干问题初探

探讨离散源撞击下结构生存力研究中的若干问题。首先从结构生存力的概念出 发,给出了结构生存力的定义,接着讨论了影响结构抗撞击生存力的若干因素,并提 出了几种针对不同撞击情况和失效准则的结构抗撞击生存力指标,最后指出了提高 结构抗撞击生存力应重视的一些研究方向。     

Operation survivability of civil aircraft

The fulfillment of the standard requirements for fatigue and damage tolerance of aircraft structures is the basis for ensuring their safe operation. The paper analyzes the rules formulated in the U.S. FAA Standards and Recommendation Circulars, Soviet Airworthiness Standards, and Russian Aviation Rules. The main requirements for ensuring the damage safety, damage tolerance, and preventing widespread fatigue damages in operating aircraft structures are stated. The results of studying the multiple site damages of full-scale aircraft structures are presented. The principle of the staged increase in the service life limit of Russian aircraft is considered. The rules of Russia are noted to be harmonized with the rules of the United States and Europe. The values of design service lives, scales of fatigue tests of full-scale structures and flight times in operation of different aircraft types are presented. The required values of the statistical and cyclical fracture resistance of structural materials are substantiated, and the achieved values of these characteristics in modern aluminum alloys are presented.     

飞机战斗损伤基本形式研究

飞机战斗损伤的基本形式是飞机复合型战伤模式研究和飞机战伤抢修针对性训练研究的基础。针对常规作战中飞机遭到导弹和炮弹攻击的特点,通过飞机实弹打击试验和空中战伤等事例分析,研究提出了切槽、剥落、性能改变、窝坑、破孔、变形、裂缝、表面伤、烧伤、折断、缺口、连接松动、卡滞、断路、短路、接触不良和软损伤共17种飞机战伤基本形式,并分析了其形成的原因,可为飞机战伤仿真、战伤评估和战伤抢修预案的制订等提供依据。     

Estimation of damage probability of combat vehicle components based on modeling and simulation

Journal of Mechanical Science and Technology - Many functions are considered for the design of GCV (ground combat vehicles), which are carried out to increase the survivability of GCV from enemy...