航空发动机桨轴有限元应力分析

为了研究航空涡桨发动机桨轴在飞行试验中所受的载荷问题,对某型发动机桨轴进行几何建模,并运用有限元软件ANSYS对桨轴在离心力、拉力、扭矩和弯矩作用下的应力进行了仿真计算,得出了起飞状态下的应力分布,对桨轴贴应变片部位的应力进行了分析,得出弯矩影响最大、扭矩次之、离心应力可以忽略的结论,为飞行试验提供了理论参考数据。     

Mg/Al合金粉末热压烧结中相变扩散过程研究

利用OLYMPUS GX71金相显微镜及EDS对Al-15％Mg热压烧结样品进行金相显微组织观察与成分分析,探讨烧结过程中组织演变过程。实验结果表明：热压烧结过程中两种粉体发生互扩散,首先在Mg颗粒边缘形成γ（Al12Mg17）相,而后随扩散的进行γ相转变为β（Al3Mg2）相,Mg颗粒由外向内不断的形成γ相,而后不断的转变为β相,直到全部生成β相。随温度的降低,β相会以极其细小的颗粒形式析出;利用真空热压烧结方法在420℃,150Mpa下保压3—4h进行固相烧结获得密度低于2．5g／cm^3致密度达98％以上的Al—15％Mg合金。     

具有弯扭掠叶片流场结构分析能力的燃气涡轮三维设计体系——弯扭掠叶片设计体系与设计思想研究之一

通过将结构分析与优化引申到气动设计中,建立了具有弯、扭、掠叶片流场结构分析能力的燃气涡轮气动设计体系,并将这一体系进一步划分为四个子体系。介绍了各子体系的构成与功能,并在流场结构分析与优化子体系中给出了流场结构三个层次的分析框架。     

高筋条壁板成型分析及成型工艺研究

AK4－1材料的高筋条壁板条拉伸成型，目前在我国飞机制造业中，不论结构还是材料、工艺成型都是全新的。这一结构及工艺成型研究对发展我国的航空制造业有着重要作用。本文阐述某型机研制中对这一新结构的多次试验过程，该材料成型时所需的热处理状态和多刀闸压工艺方法，生产出完全符合技术要求的零件。     

A critical evaluation of two Reissner–Mindlin type models for composite laminated plates

The purpose of this paper is to critically evaluate two Reissner–Mindlin type theories developed recently for composite laminated plates, namely, VAPAS (Variational Asymptotic Plate And Shell analysis) and EFSDT (Enhanced First-Order Shear-Deformation Theory). The fundamentals of both models are briefly summarized along with their unique features in comparison to most other existing models. The similarities and differences between VAPAS and EFSDT are also examined. Exact solutions of three-dimensional elasticity theory for the cylindrical bending problems are used as the arbiter to assess the accuracy of both models. Such a systematic assessment demonstrates that both models have achieved an excellent compromise between the layer-wise theories, which are accurate but computationally demanding, and the first-order shear deformation theories, which are computationally cheap but not accurate.     

Heliopause stability revisited: dispersion analysis and numerical simulations

The heliopause, a surface separating the tenuous hot heliosheath flow and the dense, strongly magnetized interstellar flow, is subject to instabilities of the Rayleigh–Taylor and Kelvin–Helmholtz types. The dynamic evolution of this discontinuity is of considerable importance for understanding the neutral atom and cosmic-ray filtration at the interface. Here, we investigate the stability of the upwind heliopause in the presence of charge exchange collisions using both an analytic (dispersion relation) approach and a numerical model that includes the interstellar magnetic field. The linear analysis yields a cubic dispersion relation that admits imaginary solutions for the full range of wavenumbers, implying that the stagnation point on the heliopause is unconditionally Rayleigh–Taylor unstable to small perturbations propagating parallel to the discontinuity surface. We confirm this result by following the nonlinear development of the instability with a time-dependent simulation using a four fluid MHD-neutral numerical code. For the typical solar wind and LISM conditions, we obtain cyclical evolution of the upwind heliopause with a period of the order of 100 years. We also identify two areas of space physics where the instability may have important implications.     

Past, present and future implications of human supervisory control in space missions

Achieving the United States’ Vision for future Space Exploration will necessitate far greater collaboration between humans and automated technology than previous space initiatives. However, the development of methodologies to optimize this collaboration currently lags behind development of the technologies themselves, thus potentially decreasing mission safety, efficiency and probability of success. This paper discusses the human supervisory control (HSC) implications for use in space, and outlines several areas of current automated space technology in which the function allocation between humans and machines/automation is sub-optimal or under dispute, including automated spacecraft landings, Mission Control, and wearable extra-vehicular activity computers. Based on these case studies, we show that a more robust HSC research program will be crucial to achieving the Vision for Space Exploration, especially given the limited resources under which it must be accomplished.     

高新航空武器装备的发展对含氟材料的需求

介绍了氟橡胶，氟涂料，氟塑料金属自润滑材料，新型膨化聚四氟乙烯的性能特点及在国内外飞机上的应用概况。由于高分子材料经氟化改性后会有更好的稳定性和更长的使用寿命，因此，设计员在设计某些有特殊功能要求的结构时，可以重点考虑上述材料。     

桥联重积分方程一种新的数值方法

纤维增强复合材料断裂力学中的桥联问题常常可归结为一个二重积分方程。常见的求解方法有矩阵迭代法和积分迭代法，但这两种方法都产复杂。本文给出一种新的分段插值方法，对此积分方程进行求解。数值计算结果表明，该方法效果令人满意。