无水溶胶-凝胶法制备非氧化物陶瓷的研究进展

综述了基于氨解、胺解以及碳化二亚胺化三类反应的无水相溶胶-凝胶方法在制备SiCN、B(C)N、SiN、BN等非氧化物陶瓷材料方面的研究进展,并对其前景进行了展望。     

参数化大型客机方案实例库研究

 为充分利用和借鉴已有的大型客机方案实例信息,建立了参数化大型客机方案实例库,并在一个开放式飞机总体设计环境中完成了方案实例三维建模和相关参数入库,提出了面向对象的参数化实例方法。在此基础上实现了对实例库中客机参数的管理、参数分析,并通过初始布局方案的模块化设计,为总体设计阶段新方案的快速设计及初步分析奠定了一定的基础。最后通过应用示例说明了实例库在总体设计阶段的运用。     

A guidance law for UAV autonomous aerial refueling based on the iterative computation method

The rendezvous and formation problem is a significant part for the unmanned aerial vehicle（UAV） autonomous aerial refueling（AAR） technique. It can be divided into two major phases： the long-range guidance phase and the formation phase. In this paper, an iterative computation guidance law（ICGL） is proposed to compute a series of state variables to get the solution of a control variable for a UAV conducting rendezvous with a tanker in AAR. The proposed method can make the control variable converge to zero when the tanker and the UAV receiver come to a formation flight eventually. For the long-range guidance phase, the ICGL divides it into two sub-phases： the correction sub-phase and the guidance sub-phase. The two sub-phases share the same iterative process. As for the formation phase, a velocity coordinate system is created by which control accelerations are designed to make the speed of the UAV consistent with that of the tanker.The simulation results demonstrate that the proposed ICGL is effective and robust against wind disturbance.     

亚毫米级弹丸光电探测技术

本文在片光遮挡式弹丸探测技术基础上发展了光电阵列探测亚毫米级弹丸技术,论述了光电阵列探测亚毫米弹丸的技术原理,详细介绍了光电阵列探测系统的探测光路和探测电路设计方案,研制了光电阵列探测系统的动态试验验证装置。在超高速碰撞靶上开展了动态验证试验,试验结果表明,采用光电阵列探测技术,大幅提高了弹丸信号的信噪比,能够可靠探测直径为0．6mm 的高速弹丸,通过分析表明该技术能可靠应用于直径为0．1mm高速弹丸的探测。     

Drop test and crash simulation of a civil airplane fuselage section

Crashworthiness of a civil airplane fuselage section was studied in this paper. Firstly, the failure criterion of a rivet was studied by test, showing that the ultimate tension and shear failure loads were obviously affected by the loading speed. The relations between the loading speed and the average ultimate shear, tension loads were expressed by two logarithmic functions. Then, a vertical drop test of a civil airplane fuselage section was conducted with an actual impact velocity of6.85 m/s, meanwhile the deformation of cabin frame and the accelerations at typical locations were measured. The finite element model of a main fuselage structure was developed and validated by modal test, and the error between the calculated frequencies and the test ones of the first four modes were less than 5%. Numerical simulation of the drop test was performed by using the LS-DYNA code and the simulation results show a good agreement with that of drop test. Deforming mode of the analysis was the same as the drop test; the maximum average rigid acceleration in test was 8.81 g while the calculated one was 9.17 g, with an error of 4.1%; average maximum test deformation at four points on the front cabin floor was 420 mm, while the calculated one was 406 mm, with an error of 3.2%; the peak value of the calculated acceleration at a typical location was 14.72 g, which is lower than the test result by 5.46%; the calculated rebound velocity result was greater than the test result 17.8% and energy absorption duration was longer than the test result by 5.73%.     

二维激波管有障碍物的激波反射流场计算

本文应用最小耗散的混合格式及MacCormack二阶格式加θq╱2耗散修正格式计算了一维激波管Riemann问题、二维激波管中激波与楔的反射流场。这两个格式的特点是对任何初值其耗散项永远不等于零,因而,计算得到的解为物理解,而且除间断外,均具有一致二阶精度,计算出的单波很精确,并且激波分辨度高。本文计算了楔角θ~*=30°、45°,激波马赫数M_s=5.29、10的情况,给出了流场的非定常过程及流场的自模解,一维结果与Riemann问题理论解、二维结果与实验结果的比较,说明计算是成功的。     

大迎角涡流的同步迭代算法

 基于多重线涡模型(MLVM),本文建立了一种计算机时少、收敛性强的适用于大迎角涡流势流数值模拟的迭代算法。采用本文算法,首次得到了迎角直到60°的旋转体涡流的收敛解。计算出的空气动力数据与实验结果吻合。     

飞机客舱工业设计要素分析和设计方法研究

安全、舒适、经济、美观的飞机客舱可为乘客提供良好的乘坐体验,增强国产商用飞机的市场竞争力。本文学习国外成功经验,研究飞机客舱工业设计的发展,分析客舱工业设计的四个要素,介绍三种适用于飞机客舱的工业设计方法;结合航空市场趋势,寻求客舱经济性和舒适性之间的平衡点,确定合适的客座数和客舱座位布局;采用感性工学设计法和虚拟现实设计法,从安全、乘客需求、CMF 和航空公司的角度,以某宽体飞机为例,设计其客舱内部空间及舱内设施设备。结果表明：本文的设计方法正确、可行,可为正在研制中的大型客机提供理论依据和设计参考。     

碳纤维复合材料方形薄壁梁在弯曲和扭转联合作用下的试验研究和结果分析

本文介绍了以M40碳纤维为增强材料的方形薄壁梁,在承受弯曲和扭转联合作用下的应变分布;扭转变形的测定;梁的破坏载荷的确定。所测试验数据稳定,说明构件制造工艺可靠,满足产品的强度、刚度要求。该结构已用于实际产品上,取得比较满意的结果。     

多功能气动测量仪的研制

是一种新型浮子式气动量仪。它不仅可以测量内径、外径和直线度误差,还可以测量孔中心距、锥度和同轴度、垂直度等位置误差。主要特点是:1.在测量位置误差时,由于设计了气动差动机构,气路中不再需要特殊的气动稳压器。气源在0～1.5×10~5Pa 范围内波动,对测量精度无影响。2.工件在量头上的安放位置及孔径尺寸变化对测量结果没有影响。