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971.
IMPROVEMENTSINMECHANICALPROPERTIESOFSINGLECRYSTALSUPERALLOYNASAIR100GuoXiping;ShiZhengxing;FuHengzhi(DepartmentofMalerialsSci... 相似文献
972.
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. 相似文献
973.
栽体磁场的干扰是导致地磁导航精度较低的主要因素,在对无人机载体磁场干扰地磁场产生的地磁测量误差简要分析的基础上,将小姿态时地磁匹配导航采用的12系数误差补偿模型引入一种无人机地磁定向导航的罗差修正.在静态条件下,利用无磁转台分别获取无人机在±30°姿态角范围内有无干扰源的磁测数据.实验数据分析表明,通过补偿,栽体航向角在±5°范围内其误差均方差由2.174°下降到0.350°,其余角度下航向角误差均方差则由2.282°下降到0.732°,满足无人机在大角度姿态飞行时航向稳定度优于±3°的要求. 相似文献
974.
复合材料结构界面失效分析有助于复合材料整体化结构细节设计,有必要进行界面失效问题分析.针对复合材料整体化结合界面进行有限元数值模拟失效分析方法研究,对承受不同载荷的结合界面选用不同的建模方法和失效模型.对于层压板失效,在Tsai-Hill判据基础上,增加破坏能判据;对于界面失效,提出基于应力、应变和破坏能的多级判据及其衰减方法.结果表明:本文方法建模简单、计算速度较快、计算结果与试验值吻合性好,可为复合材料整体化结构设计提供工程实用的分析方法. 相似文献
975.
In this study, a new GVS(Ground Volcanic Scoria) lunar regolith simulant was produced. The similarity between GVS and lunar soil was proved by comparison with Apollo lunar soil samples and other commercial lunar soil simulants. Then, GVS lunar regolith simulant was investigated as the source material for preparing geopolymer to produce building material for lunar colony construction. To study the possibility of preparing geopolymer from GVS lunar regolith simulant and the optimum activator formu... 相似文献
976.
977.
本文运用二维约化摄动方程推导出彗尾剪彻磁流体的修正B-KdV方程,并定性讨论了其非线性性态。主要结论是:(1)推导出彗尾剪切磁流体修正的B-KdV方程,(2)给出彗尾宏观非线性波动与剪切背景的制约关系,(3)定性地解释了彗尾等离子体的一些复杂结构,(4)给出太阳风与彗尾等离子体相互作用的一种输运机制。 相似文献
978.
为设计效率高,体积小的航空钐钴永磁直流电动机,首先从电动机电磁设计原则和航空产品特点出发,确定其电、磁负荷的取值,进而以最小体积,最高效率为目标函数,对电枢外径、电枢铁心长度、电枢冲片的槽形尺寸以及槽数等结构参数进行优化设计,从而使设计的产品很好地满足了各项技术要求。 相似文献
979.
We describe the present status of the project of the Taiwan Oscillation Network (TON) and discuss a scientific result using
the TON data. The TON is a ground-based network to measure solar intensity oscillations for the study of the solar interior.
Four telescopes have been installed in appropriate longitudes around the world. The TON telescopes take K-line full-disk solar
images of diameter 1000 pixels at a rate of one image per minute. The data has been collected since October of 1993. The TON
high-spatial-resolution data are specially suitable for the study of local properties of the Sun. In 1997 we developed a new
method, acoustic imaging, to construct the acoustic signals inside the Sun with the acoustic signals measured at the solar
surface. From the constructed signals, we can form intensity map and phase-shift map of an active region at various depths.
The direct link between these maps and the subsurface wave-speed perturbation suffers from the poor vertical resolution of
acoustic imaging. Recently an inversion method has been developed to invert the measured phase travel time perturbation to
estimate the distribution of wave-speed perturbation based on the ray approximation. This technique of acoustic imaging has
been used to image the far-side of the Sun that could provides information on space weather prediction.
The TON Team includes: Antonio Jimenez (Instituto Astrofisica de Canarias, Spain); Guoxiang Ai and Honqi Zhang (Huairou Solar
Observing Station, P.R.C.); Philip Goode and William Marquette (Big Bear Solar Observatory, U.S.A.); Shuhrat Ehgamberdiev
and Oleg Ladenkov (Ulugh Beg Astronomical Institute, Uzbekistan)
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
980.
层合板柱面弯曲成型模压分布与回弹问题 总被引:2,自引:0,他引:2
通过引入剪切变形效应,提出解决多层叠合板在压模中弯曲成指定柱面形状时的模压分布,以及粘合固化后卸模时回弹计算这样一个包括力学正问题与反问题的有效分析方法,并得到了典型封闭形式解答,同时给出计算与实验结果,二者差异在工程精度的允许范围内。 相似文献