飞机矩形气密舱尺寸对气密变形的影响

为了得到不同长宽比的飞机矩形气密舱在内压载荷作用下的变形规律,构造了飞机矩形气密舱的理论计算模型,建立了静力平衡方程,基于小变形理论,推导了矩形气密舱气密载荷下的变形方程,理论计算与有限元分析所得的变形值偏差小于1.2%。研究发现,对于受内压的不同长宽比矩形气密舱,气密舱长边始终产生向外凸的变形,随着长宽比值的增大,气密舱短边的变形呈现全部外凸一两端局部内凹一W型内凹-全部内凹的变形规律。研究结果可应用于飞机矩形气密舱尺寸选择和变形控制。     

直升机机体结构减振优化设计

直升机在飞行过程中,由于旋翼空气动力学环境及结构的特殊性,旋翼桨叶受到周期性的气动载荷使桨叶产生弹性振动,在桨叶内部引起结构振动载荷,其振动载荷沿桨毂传到机体上,引起机体的振动响应,从而形成直升机严重的振动问题。为了解决直升机机体的振动问题,基于 Patran/Nastran 有限元软件,对型号直升机机身进行动力学特性分析,研究旋翼载荷和机体结构等方面对机体振动的影响,并集成 Isight 优化软件对其进行结构优化分析,从而达到机体减振的效果。     

树脂基防隔热复合材料高温响应分析方法研究进展

针对树脂基防隔热复合材料高温条件下复杂的热/力/化学的多场耦合问题，从高温性能预报模型、高温响应求解方法和高温试验测试三方面进行了论述。详细介绍了研究树脂基防隔热复合材料高温响应相关的热解动力学模型、材料高温热物性及力学性能演化表征方法、材料高温响应模型的求解方法以及表征材料高温响应的多种高温试验测试手段。对上述研究方法的发展进行了评述，并对未来发展趋势进行了展望。本文有助于相关研究人员认识和发展树脂基复合材料在高温下的热力响应分析方法，也可供工程技术人员对这类材料的防隔热性能和高温承载性能进行研究。     

基于力位协同控制的大飞机机身壁板装配调姿方法

为校正中机身壁板由于重力和调姿内力产生的变形，提高中机身壁板装配调姿精度，提出了一种基于力位协同控制的装配调姿方法。通过将调姿机构等效为并联机构，推导了调姿机构的解析正反解模型；根据螺旋理论，建立了力传感器测量值与重力、调姿内力之间的映射关系，实现重力补偿值的动态计算，基于局部刚体-弹性连接假设，通过多元线性回归方法构建了调姿内力转化为位置补偿量的模型；根据Clamped-Free变形协调原理，简化了定位器调姿内力之间的协调关系，在此基础上提出了重力前馈补偿和调姿内力转化为位置补偿的力位协同控制策略，并对其进行了理论分析与设计。最后，对所提出的控制策略进行了仿真分析，结果表明采用力位协同控制方法，调姿定位精度提高35.3%，调姿内力降低77.8%，通过应用实验，说明了该方法的可行性和有效性。     

DC-CD变换器控制技术研究与实现

DC-DC变换器工作在额定负载时，输入电压会出现扰动。工作在额定输入电压时，负载电阻也会发生突变。为了实现宽电压输入，保证变换器具有较高的输入电压调整率和负载调整率，设计了自动切换与控制策略。根据Buck-Boost型DC-DC变换器的工作特点，计算出开关的导通与关断时间点，从而精确地控制开关动作。基于并行运算和组合逻辑，在Matlab中搭建了模型，并进行了仿真和试验验证。结果表明，提出的控制方法能够有效地克服负载电流突变和输入电压扰动对变换器性能的影响。     

新一代战斗机座舱盖关键技术与设计方案

座舱是战斗机三大电磁散射源之一，座舱盖雷达散射截面（RCS）的减缩技术是实现新一代战斗机全机雷达隐身性能的关键技术。基于新一代战斗机隐身外形平台，座舱盖在隐身技术、透明件结构、抗鸟撞、弹射救生、光学性能、结构变形控制等领域均面临新的挑战。本文以新一代战斗机为背景，研究了座舱盖性能提升的4项关键技术：座舱盖隐身性能提升技术、大型整体座舱盖透明件结构设计技术、复杂曲面座舱盖光学性能仿真优化技术、大尺寸活动部件变形及状态控制技术。经过上述关键技术研究，完成了新一代战斗机座舱盖设计技术体系的升级，促进了新一代战斗机座舱盖技术和性能的跨代提升。     

Machining deformation of single-sided component based on finishing allowance optimization

Owing to reliability and high strength-to-weight ratio, large thin-walled components are widely used in the aviation and aerospace industry. Due to the complex features and sequence involved in the machining process of large thin-walled components, machining deformation of component is easy to exceed the specification. In order to address the problem, it is important to retain the appropriate finishing allowance. To find the overall machining deformation, finishing allowance-induced deformation (web finishing allowance, sidewall finishing allowance) and initial residual stress-induced deformation were considered as major factors. Meanwhile, machined surface residual stress-induced deformation, clamping stress-induced deformation, thermal deformation, gravity-induced deformation and inertial force-induced deformation were neglected in the optimization model. Six-peak Gaussian function was introduced to fit the initial residual stress. Based upon the obtained function of initial residual stress, a deformation prediction model between initial residual stress and finishing allowance was established to attain the finishing allowance-induced deformation. In addition, linear programming optimization model based on the simplex algorithm was developed to optimize the overall machining deformation. Results have concluded that the overall machining deformation reached the minimum value when sidewall finishing allowance and web finishing allowance varied between 1 and 2 mm. Additionally, web finishing allowance-induced deformation and sidewall finishing allowance-induced deformation were 1.05 mm and 0.7 mm. Furthermore, the machining deformation decreased to 0.3–0.38 mm with the application of optimized finishing allowance allocation strategy, which made 39–56% reduction of the overall machining deformation compared to that in conventional method.     

Dynamics response analysis of airborne external storage system with clearance between missile-frame

Considering the aircraft and its external components are subjected to complex and variable aerodynamic loads during the working process, the missile-frame clearance system of the airborne external missile is investigated. The random vibration characteristics of the airborne external components are analyzed by finite element method. The finite element model is optimized with reference to the test results, and the effects of different clearance on the dynamic response of the missile-frame system are compared. The result shows that the frequency response curves of the same position and the resonant peak frequencies are consistent under different clearances. The acceleration response at both ends of the missile is large and the amplitude near the center of mass is gentle. The results can be used to predict reasonable missile-frame clearance and make guidance to the structural design and reliability analysis of the missile-frame system.     

薄板光学反射面面形变形驱动器集成设计

针对某光学载荷薄板反射面面形调整需求,对一种新型精密微调驱动器开展了集成设计研究。分析了柔性太阳翼冷热交变对敏感载荷的影响,设计了一种基于巨磁致伸缩材料(GMM)的主动补偿驱动器,对驱动器关键部件进行了优化。建立了驱动器的动力学模型,并利用模糊自适应PID算法对其进行闭环控制。仿真结果表明:设计的驱动器能实现较大的行程、较高的定位精度,可用于面形变形补偿。