中国科学院机构知识库网格系统: 检索

A Nodal Finite Element Method for a Thermally Coupled Eddy-Current Problem with Moving Conductors 期刊论文 OAI收割
COMMUNICATIONS IN COMPUTATIONAL PHYSICS, 2021, 卷号: 29, 期号: 3, 页码: 767-801
作者: Wang, Zezhong; Hu, Qiya

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收藏 | 浏览/下载：23/0 | 提交时间：2021/04/26

Thermally coupled eddy-current problem finite element method time step-length iteration Picard iteration optimal error estimates preconditioner

Dynamics calculation for variable-length underwater cable with geometrically nonlinear motion 期刊论文 OAI收割
Ocean Engineering, 2020, 卷号: 212, 页码: 1-19
作者: Quan WC(全伟才); Chang, Qingqing; Zhang QF(张奇峰); Gong, Jun

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收藏 | 浏览/下载：34/0 | 提交时间：2020/08/01

Variable-length Underwater cable Dynamics calculation Nonlinear finite element Geometrically nonlinear motion

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：62/0 | 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.

Structural design for lightweight off-axis TMA space telescope (EI CONFERENCE) 会议论文 OAI收割
2011 2nd International Conference on Digital Manufacturing and Automation, ICDMA 2011, August 5, 2011 - August 7, 2011, Zhangjiajie, Hunan, China
作者: Li Z.; Li Z.

收藏 | 浏览/下载：36/0 | 提交时间：2013/03/25

A kind of small space telescope with 1m focal length was designed. By adopting finite element analysis technique the structure of the space telescope was analyzed. The analysis results indicate that the surface profile accuracy of the mirrors reach to RMS 8.0nm with the working circumstances 4C uniform temperature change and space micro-gravity the base frequency of the structure was 115 Hz. It shows that the designed structure has sufficiently high dynamic and static stiffness and thermal dimensional stabiLity. This space optical telescope is very suitable for little satellite application. 2011 IEEE.

Research on lightweight outer baffle for coaxial space camera (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Electronic and Mechanical Engineering and Information Technology, EMEIT 2011, August 12, 2011 - August 14, 2011, Harbin, China
作者: Zhang L.; Zhang L.

收藏 | 浏览/下载：17/0 | 提交时间：2013/03/25

Stray light is non-imaging light that reach the optical system imaging plane. The non-imaging light can be received by detector if it is not effectively controlled and stray light which directly irradiates on the detector has great influence on the imaging quality. Stray light can be effectively inhibited if the outer baffle of space camera is designed optimally. Carbon fiber composite material is chosen as main material to meet requirements of a coaxial space optical system. The outer baffle should have advantages such as lightweight high stiffness and dimensional stability etc. Using optimization design tools the lightweight outer baffle is designed. And finite element method is used to check the structure. Development and test results show that the outer baffle with a diameter of 620mm and a total length of 1200mm only weighs 7.3kg. And the baffle's natural frequency reaches 88Hz and it can satisfy the requirements of the space camera. 2011 IEEE.

Investigation on the effect of crack length on mechanical properties of functionally graded materials 会议论文 OAI收割
2010 International Conference on Frontiers of Manufacturing and Design Science, ICFMD2010, Chongqing, China, DEC 11-12, 2010
作者: Zhao XY(赵希宇)

收藏 | 浏览/下载：21/0 | 提交时间：2013/02/26

Coatings Cracks Creep Finite element method Human engineering Manufacture Mechanical properties Stress intensity factors Thermal barrier coatings Crack length Crack tip fields Finite Element Functionally graded Maximum displacement Numerical results Principal stress Pure metals Stress intensity Thermal barrier Thermo-mechanical Work environments

ADHESIVE MECHANISMS OF A BIO-INSPIRED NANO-FILM 会议论文 OAI收割
3rd International Conference on Heterogeneous Material Mechanics (ICHMM 2011), Shanghai, PEOPLES R CHINA, MAY 22-26, 2011
作者: Chen SH(陈少华); Peng ZL(彭志龙)

收藏 | 浏览/下载：30/0 | 提交时间：2012/04/01

gecko spatula finite nano-film adhesive length surface roughness

Design of the infrared dual-band athermalized optical system based on HDE (EI CONFERENCE) 会议论文 OAI收割
International Symposium on Photoelectronic Detection and Imaging 2009: Advances in Infrared Imaging and Applications, June 17, 2009 - June 19, 2009, Beijing, China
作者: Zhang L.; Sun Q.; Wang H.; Wang H.; Wang H.

收藏 | 浏览/下载：97/0 | 提交时间：2013/03/25

A dual-band infrared optical system adopting an uncooled LW infrared detector and a cooled MW infrared detector is designed and manufactured while in the LW IR band the F/# is 1 and the focal length is 114 mm based on the athermal ability and special diffractive properties of harmonic diffractive elements. The design shows in the MW IR band the F/# is 2 and the focal length is 72 mm for the temperature range -40 70 the MTF value is over 0.5 at 10 lp/mm. Finite element method is applied to the opto-mechanic structure of the system for thermal analysis for the temperature range -40C 70C the MTF value is over 0.4 at 20 lp/mm which confirms the imaging ability of the system in a wide temperature range. 2009 SPIE.

Standard enthalpies of formation of finite-length (5,5) single-walled carbon nanotube 期刊论文 OAI收割
Journal of Nanoparticle Research, 2008, 卷号: 10, 期号: 6, 页码: 1037-1043
C. H. Sun; G. Q. Lu; H. M. Cheng

收藏 | 浏览/下载：12/0 | 提交时间：2012/04/13

standard enthalpy of formation finite-length carbon nanontube stability modeling and simulation density function theory molecular-orbital methods electronic-structure thermodynamic properties energy fullerenes hydrocarbons aromaticity stability

A numerical study of grain size effects on the strength and elongation of Al polycrystals using strain gradient plasticity theory 期刊论文 OAI收割
International Journal of Materials Research, 2008, 卷号: 99, 期号: 2, 页码: 191-196
L. Zhou; S. X. Li; W. Ke

收藏 | 浏览/下载：21/0 | 提交时间：2012/04/13

strain gradient plasticity classical plasticity finite element method Al polycrystals size effect matrix composites particle-size length scale aluminum deformation ductility