中国科学院机构知识库网格系统: 检索

Analysis of sealing characteristics of rolling blinds window for large aperture laser emission system 期刊论文 OAI收割
Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering, 2019, 卷号: 48, 期号: 5
作者: T.Ren; S.Shao; L.Meng; K.Wang

|

收藏 | 浏览/下载：15/0 | 提交时间：2020/08/24

Finite element method,Electric drives,High power lasers,Laser optics,Tensile strength

Effect of Ta addition on the microstructures and mechanical properties of in situ bi-phase (TiB2-TiCxNy)/(Ni-Ta) cermets 期刊论文 OAI收割
Ceramics International, 2019, 卷号: 45, 期号: 4, 页码: 4408-4417
作者: H.Y.Yang; Z.Wang; S.L.Shu; J.B.Lu

|

收藏 | 浏览/下载：27/0 | 提交时间：2020/08/24

Cermets,Ta content,Mechanical properties,high-temperature synthesis,combustion synthesis,high-strength,ti-c,compression properties,tantalum content,composites,behavior,zr,(ticxny-tib2)/ni,Materials Science

Structural design of large aperture rectangular mirror for space telescope (EI CONFERENCE) 会议论文 OAI收割
2nd International Conference on Civil Engineering and Transportation, ICCET 2012, October 27, 2012 - October 28, 2012, Guilin, China
作者: Li Z.; Li Z.

收藏 | 浏览/下载：26/0 | 提交时间：2013/03/25

Structural design of large aperture mirror is one of the key technologies for space telescope development. To meet the requirements of high stiffness strength and thermal dimensional stability some factors such as support scheme materials selection lightweight design and flexible support design were taken into account. The three supports location of the mirror was determined according to the modal analytical solution. By adjusting the parameters of flexure hinge influences of gravity assembly stress and thermal stress on the mirror were reduced obviously. Finite element analysis (FEA) results indicate that the surface accuracy reach to rms10.2nm and 10.8nm under the gravity along optical axis direction and 5C uniform temperature rise respectively the fundamental frequency of the mirror component is 268Hz. Dynamics test shows that the first order natural frequency is 256Hz which shows an error less than 5% compared to FEA results. (2013) Trans Tech Publications Switzerland.

Image mosaic technique based on the information of edge (EI CONFERENCE) 会议论文 OAI收割
2012 3rd International Conference on Digital Manufacturing and Automation, ICDMA 2012, July 31, 2012 - August 2, 2012, Guilin, Guangxi, China
作者: Wang Y.-Q.

收藏 | 浏览/下载：27/0 | 提交时间：2013/03/25

Image mosaic is an important branch in the field of image processing. This paper designs and realizes an image mosaic technique based on the information of edge. The technology is suitable for engineering application. First of all two images of the adjoining frames are processed by convolution operation get the edge images. And then we cut edge image into pieces and compute their spatial frequency. According to the value of the spatial frequency select reasonable registration model group. We compute correlation strength and the value of movement offset which are the model group and the current frame edge image. We can complete image mosaic by them. We use video sequence which of the resolution is 1024 * 768 do the experiment. The results show that the method has good effect and strong adaptability. Algorithm is high efficiency which running time is 24 ms. It is suitable for real-time processing requirements of the application. This method is an effective mosaic technique which is suitable for engineering application. 2012 IEEE.

Study on ultra-light secondary baffle for coaxial two-mirror telescope (EI CONFERENCE) 会议论文 OAI收割
2012 9th IEEE International Conference on Mechatronics and Automation, ICMA 2012, August 5, 2012 - August 8, 2012, Chengdu, China
作者: Zhang L.; Zhang L.

收藏 | 浏览/下载：44/0 | 提交时间：2013/03/25

The coaxial two-mirror telescope consists of two mirrors facing each other. Classical two-mirror arrangements are Gregorian and Cassegrain. These systems are usually applied to space telescopes and often have optical baffles to prevent stray light from entering the focal plane. The optical baffles consist of concentric rings suspended between the secondary and the primary mirror. The secondary baffle for a large two-mirror optical system is designed and analyzed in this paper. According to mission of a telescope the structure should have high stiffness and high reliability and light weight. Compared with invar aluminum alloy and titanium alloy carbon fiber composite is currently the best material in terms of weight-to-strength ratio. It also has advantages of high temperature tolerance and low thermal expansion. So carbon fiber composite is chosen as material to meet requirements of the coaxial telescope. In this paper optimization method based on finite element analysis (FEA) is used for design the secondary baffle. Minimum weight of the baffle is chosen as an objective function. Thicknesses of former tube and vanes are chosen as variables. Analysis results show that the designed secondary baffle has maximum diameter of 180mm total length of 120mm and weighs 142g. And its fundamental frequency reaches 651Hz. Therefore the baffle has many advantages such as ultra-light weight high stiffness and dimensional stability etc. The optimization method and the baffle design can be helpful to other coaxial telescopes such as Cassegrain Gregorian and their subdivisions. 2012 IEEE.

Lightweight design and analysis of support structure of certain UAV engine (EI CONFERENCE) 会议论文 OAI收割
2012 International Conference on Electrical Insulating Materials and Electrical Engineering, EIMEE 2012, May 25, 2012 - May 27, 2012, Shenyang, Liaoning, China
Xing X.; Liu B.; Han X.; Jia H.

收藏 | 浏览/下载：24/0 | 提交时间：2013/03/25

Support structure of UAV (Unmanned Aerial Vehicle) engine is the important support for UAV engine playing a support role and bearing extremely complex load so its lightweight strength and dynamic characteristics have a great influence on high performance of UAV. This paper focuses on UAV having the requirement of high performance and stability to the support structure of engine and uses the software of MSC.Patran and MSC.Nastran and topology optimization criterion to lightweight design and analysis the support structure of UAV engine under the premise condition of existing constraints. Then the static strength and modal are analyzed for the result of lightweight design and the strength of the model and dynamic characteristics are verified. (2012) Trans Tech Publications Switzerland.

Research on defect detection technology of C/C composite (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Advanced Engineering Materials and Technology, AEMT 2011, July 29, 2011 - July 31, 2011, Sanya, China
作者: Li W.; Wang H.; Wang H.; Wang H.; Wang H.

收藏 | 浏览/下载：27/0 | 提交时间：2013/03/25

Carbon matrix/Carbon fibre reinforced composite(C/C composite) has many special characteristics such as high strength high elastic modulus high temperature resistance and ablation resistance. So it is used to manufacture rocket engine nozzle in aerospace filed. But its security will be seriously effected during rocket engine working due to the manufacturing defects. Based on analyzing defect types and structure characteristic of C/C composite the ultrasonic and infrared testing methods on C/C composite are further studied in this thesis. and effective defect detection has been achieved. (2011) Trans Tech Publications.

Study on the azimuth bearing scheme of a large Alt-azimuth telescope (EI CONFERENCE) 会议论文 OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Large Mirrors and Telescopes, April 26, 2010 - April 29, 2010, Dalian, China
作者: Wang H.; Dai S.; Zhang J.; Wang H.; Zhang J.

收藏 | 浏览/下载：30/0 | 提交时间：2013/03/25

The azimuth bearing schemes in typical large Alt-azimuth telescopes especially the 3.5-m APO telescope and the 4.1-m SOAR telescope were analyzed. A scheme of high-angular contacted thrust ball bearing integrated with a radial ball bearing was put forward. According to the Hertz contact theory the corresponding parameters were designed for engineering application. The static performance parameters within the range of 60 85 original contact angle were calculated. Compared with the traditional plane thrust ball bearing the results shows that the high-angular (80) contact thrust ball bearing has more benefits at bearing strength and rigidity for large telescope. The 1500mm diameter prototyping bearing shows good performance including the axial jitter is 0.009mm the radial jitter is 0.006mm the maximum starting torque without load is 30N·m and the load capacity is more than 30t which offers advanced technique path for the buildup of the high precision azimuth shafting and the whole telescope system. 2010 Copyright SPIE - The International Society for Optical Engineering.

Manufacture of 1.2m reaction bonded silicon carbide mirror blank CFID (EI CONFERENCE) 会议论文 OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Large Mirrors and Telescopes, April 26, 2010 - April 29, 2010, Dalian, China
作者: Zhang G.; Zhang G.; Zhang G.

收藏 | 浏览/下载：16/0 | 提交时间：2013/03/25

Silicon carbide (SiC) is a new type candidate material for large-scale lightweight space mirror. Its low thermal distortion high stiffness fine optical quality and dimensional stability make SiC an ideal material for large space born telescope. Since ten years Changchun institute optics fine mechanics and physics (CIOMP) has developed reaction bonded SiC (RB-SiC) technology for space application and can fabricate RB-SiC mirror with scale less than 1.0 meter for telescope. The green body is prepared with gel-casting method which is an attractive new ceramic forming process for making high-quality complex-shaped ceramic parts. And then unmolding drying binder burning out reacting bonded the RB-SiC can be obtained. But with the development of space-born or ground telescope the scale of primary mirror has exceeded 1.0 meter. So CIOMP has developed an assembly technique which called novel reaction-formed joint technology for larger RB-SiC mirror blank. The steps include joining of green bodies with mixture comprised of SiC particles and phenolic resin etc firing machining and sintering. Joining the 1.2 meter RB-SiC mirror blank by the novel reaction-formed joint technology. And testing the welding layer's performance the results show that the thickness of 54-77m the microstructure and thermal property can be comparable to the substrate and the mechanical property are excellent in bending strength of 307MPa. 2010 Copyright SPIE - The International Society for Optical Engineering.

Fabrication technique of large-scale lightweight SiC space mirror (EI CONFERENCE) 会议论文 OAI收割
3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies, AOMATT 2007: Large Mirrors and Telescopes, July 8, 2007 - July 12, 2007, Chengdu, China
作者: Zhang G.; Zhang G.; Zhang G.

收藏 | 浏览/下载：13/0 | 提交时间：2013/03/25

Silicon carbide (SiC) is a new type candidate material for large-scale lightweight space mirror. Its low thermal distortion high stiffness high optical quality and its dimensional stability are better than other traditional optical substrate materials such as ULE Zerodure Beryllium (Be) and so on. In this paper the lightweight silicon carbide space mirror blank was fabricated by reaction sintering. As a space born mirror material silicon carbide must be an optical grade ceramic. So we prepared the silicon carbide green body with gel-casting method. Then some carbon materials were supplemented into the green body which will bring reaction-sintering with silicon in a vacuum furnace during 1500-1600C ultimately the reaction bonded silicon carbide was made. The diameter of SiC space mirror blank we have made is 680mm. If expanding the size of the vacuum furnace bigger mirror blank can be obtained. The test results show that the mechanical and thermal properties of RB-SiC are excellent with bending strength of 350MPa fracture toughness of 4.1 MPa·m1/2 and coefficient of thermal expansion(CET) of 2.6710-6/K. The surface roughness(RMS) could be better than 3nm.