金属蒙皮破孔结构胶铆混合修理的疲劳性能研究

蒙皮破孔是最典型的飞机战伤形式之一,目前对其抢修的方式主要有纯铆接修理和纯胶接修理,在修复效果或修复时间上存在不足。提出利用胶铆混合方式进行蒙皮破孔修理,采用疲劳试验与有限元分析方法,针对带预置圆形破孔损伤的破孔件、铆接修理件、胶接修理件和胶铆混合修理件进行疲劳性能对比研究。结果表明：相比纯铆接和纯胶接修理方式,胶铆混合连接方式具有最佳的修理效果,混合连接中铆钉作用能有效提高胶层承载并抑制胶层剥离;胶铆混合修理方式与纯铆接相比疲劳性能更优,与纯胶接相比修理时间更短,在金属蒙皮破孔结构的战伤抢修工作中具有良好的应用前景。     

大型复杂锯齿形化铣蒙皮成形工艺分析与优化

针对形面复杂、成形工艺流程长、加工难度大的复杂化铣类锯齿蒙皮零件,以飞机外蒙皮为例,对零件的形面特点及加工工艺难点进行分析。采用技术方案理论分析及 ABAQUS 有限元仿真模拟成形过程技术,对复杂锯齿蒙皮采用蒙皮拉伸成形加工过程中遇到的难点及蒙皮拉伸成形中锯齿蒙皮零件内部结构的应力、应变分布、整体变形、减薄,以及充分回弹后与工装的贴合情况进行了分析。通过有限元模拟仿真技术对蒙皮拉伸成形结果的预测,进而优化相应的工装设计结构和蒙皮拉伸成形设备的加工参数,来减少传统钣金加工零件成形过程中的试错过程,进而提高锯齿蒙皮零件的成形质量、节约工装制造费用、缩短零件制造周期。     

横肋粗糙元地表的风场阻力特征研究

使用雷诺应力模型(RSM)模拟横肋粗糙元地表的风场，将粗糙元横截面的高宽比 h/b、粗糙元间距宽度比w/b 以及间距高度比 w/h 作为粗糙表面的特征参数，利用数值方法定量研究了粗糙表面阻力随粗糙元密度的变化规律以及粗糙元横截面尺寸改变对阻力的影响。研究结果表明：粗糙元横截面尺寸改变不影响粗糙表面阻力随粗糙元分布密度的变化规律，粗糙元的间距高度比 w/h 是横肋粗糙表面的关键特征参数，且粗糙表面的平均总阻力在 w/h=7时取得最大值。     

航空救生系统实战效能评估

依据航空救生系统的战术技术指标,建立了航空救生系统的评价体系.运用灰色层次分析法和串并联系统理论,对ADC模型及其扩展模型进行修正,结合实例进行分析计算,给出了修正扩展模型下航空救生系统的效能,更有效地反映出救生系统的全面综合实战能力,给决策者提供可靠的理论依据.     

民用飞机蒙皮加筋壁板损伤容限分析方法探讨

主要介绍了民用飞机蒙皮加筋壁板损伤容限的分析方法,以中间筋条断裂的两跨纵向裂纹为例,将影响结构损伤容限特性的因素分为三部分进行计算,分别是加筋效应、鼓胀效应以及应力分布效应,最终得到相对应的裂纹尖端的应力强度因子并且进行裂纹扩展分析及剩余强度计算。文中选取实例采用这种方法进行计算,并将计算结果与试验数据对比,两者吻合较好,说明了本方法的可行性及实用性。     

Synthesis of Iron-containing Carbon Microparticles from Deoiled Asphalt and Ferrocene

The deoiled asphalt as the carbon source and the ferrocene as the metal source and the catalyst precursor were chosen to synthesize iron-containing carbon microparticles through co-carbonization at the temperature of about 450℃ for 3 h. The resulting products were treated at 2 000 ℃ for 2 h. All samples were examined by high resolution transmission electron microscopy （HRTEM） and X-ray diffraction （XRD）. The results show that the iron particles in the heat-treated material are completely coated by carbon. In addition to the fully filled carbon microparticles as well as hollow carbon ones, also form carbon fibers with hollow centers. The formation mechanism of the as-prepared products was discussed briefly.     

飞机前缘蒙皮数字化精确拉形技术

总结分析飞机前缘蒙皮的成形工艺特点。选取典型零件,设计加载轨迹方案及参数,利用有限元分析进行工艺参数优化,分析主要工艺参数对成形的影响规律。根据有限元优化结果,利用ASSFCAE FET600软件生成数控代码,进行生产性实验和测量分析,获得了合格的零件,实现飞机前缘蒙皮精确拉伸成形。     

In-plane corrugated cosine honeycomb for 1D morphing skin and its application on variable camber wing

A novel 0-Poisson’s ratio cosine honeycomb support structure of flexible skin is proposed. Mechanical model of the structure is analyzed with the energy method, finite element method (FEM) and experiments have been performed to validate the theoretical model. The in-plane characteristics of the cosine honeycomb are compared with accordion honeycomb through analytical models and experiments. Finally, the application of the cosine honeycomb on a variable camber wing is studied. Studies show that mechanical model agrees well with results of FEM and experiments. The transverse non-dimensional elastic modulus of the cosine honeycomb increases (decreases) when the wavelength or the wall width increases (decreases), or when the amplitude decreases (increases). Compared with accordion honeycomb, the transverse non-dimensional elastic modulus of the cosine honeycomb is smaller, which means the driving force is smaller and the power consumption is less during deformation. In addition, the cosine honeycomb can satisfy the deform- ing requirements of the variable camber wing.     

RESEARCH ON NURBS SKINNING SURFACE VIA COMPLEX CURVES

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基于嵌入式NT的三维电子航空图系统的设计与实现

介绍了一种基于嵌入式NT的三维电子航空图系统的设计与实现。该系统在自行研制的系统硬件基础上,采用嵌入式NT操作系统,利用国内的三维地理信息平台软件GEOSTAR,实现三维电子航空图系统。该系统采用金字塔数据结构,以达到对海量数据的实时处理能力,并具有雷达、火炮、高度报警、模拟飞行的功能。系统能根据飞机的航行状态实时显示是飞机转弯、爬升、俯冲时的三维仿真效果。