The Telescope Primary Mirror Isostatic Mount Bonding Position Analysis

2013 ◽  
Vol 284-287 ◽  
pp. 2812-2815
Author(s):  
Ming Ying Hsu ◽  
W.C. Lin ◽  
Chia Yen Chan ◽  
C. F. Ho ◽  
S.T. Chang ◽  
...  
Keyword(s):  
Finite Element ◽  
Surface Deformation ◽  
Gravity Force ◽  
Mirror Reflection ◽  
Mirror Surface ◽  
Optical Performance ◽  
Primary Mirror ◽  
Position Errors ◽  
Result Show ◽  
Alignment Process

The telescope primary mirror Isostatic Mount (ISM) design is an important issue for optical performance. The ISM bonding position will affect the telescope performance. The primary mirror reflection surface is parallel with gravity force during telescope alignment process. Thus, the distance between ISM geometry center and primary mirror center of gravity will lead mirror surface deformation. The ISM mounting mainly aberration is astigmatism at mirror surface. This study is applied Finite Element (FEM) simulate mirror surface deformation and using Zernike polynomial fitting the mirror surface aberration. The simulation result show the ISM bonding at mirror neutral plane the aberration will minimum at 1G gravity. The ISM bonding position errors also affect aberration distribution.

Optimization Analysis for Radial Support by Finite Elements Method

2012 ◽  
Vol 466-467 ◽  
pp. 734-738
Author(s):  
Cheng Ming Li ◽  
Yi Fan Wang
Keyword(s):  
Finite Element ◽  
Finite Elements ◽  
Optimal Solution ◽  
Support Point ◽  
Mirror Surface ◽  
Optimization Analysis ◽  
Primary Mirror ◽  
Finite Element Software ◽  
The Relationship ◽  
Surface Figure

Primary mirror’ surface figure is affected by supporting structure obviously. Especially for large-aperture telescope, the surface figure is significant because of primary mirror’ self-weight. For the requirement of the usage, it’s necessary to minimize the surface figure from self-weight by reasonable supporting scheme. The text optimized support point and force of radial support to minimize the surface figure by finite-element software. At the same time, it studied the relationship between support point and counterweight to reduce the weight of support structure. At last, it gave the optimal solution.

scholarly journals Design and Optimization for Mounting Primary Mirror with Reduced Sensitivity to Temperature Change in an Aerial Optoelectronic Sensor

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 7993
Author(s):  
Meijun Zhang ◽  
Qipeng Lu ◽  
Haonan Tian ◽  
Dejiang Wang ◽  
Cheng Chen ◽  
...  
Keyword(s):  
Surface Shape ◽  
Shape Error ◽  
Temperature Decrease ◽  
Mirror Surface ◽  
Optical Performance ◽  
Uniform Temperature ◽  
Primary Mirror ◽  
Optoelectronic Sensor ◽  
Thermal Adaptability

In order to improve the image quality of the aerial optoelectronic sensor over a wide range of temperature changes, high thermal adaptability of the primary mirror as the critical components is considered. Integrated optomechanical analysis and optimization for mounting primary mirrors are carried out. The mirror surface shape error caused by uniform temperature decrease was treated as the objective function, and the fundamental frequency of the mirror assembly and the surface shape error caused by gravity parallel or vertical to the optical axis are taken as the constraints. A detailed size optimization is conducted to optimize its dimension parameters. Sensitivities of the optical system performance with respect to the size parameters are further evaluated. The configuration of the primary mirror and the flexure are obtained. The simulated optimization results show that the size parameters differently affect the optical performance and which factors are the key. The mirror surface shape error under 30 °C uniform temperature decrease effectively decreased from 26.5 nm to 11.6 nm, despite the weight of the primary mirror assembly increases by 0.3 kg. Compared to the initial design, the value of the system’s modulation transfer function (0° field angle) is improved from 0.15 to 0.21. Namely, the optical performance of the camera under thermal load has been enhanced and thermal adaptability of the primary mirror has been obviously reinforced after optimization. Based on the optimized results, a prototype of the primary mirror assembly is manufactured and assembled. A ground thermal test was conducted to verify difference in imaging quality at room and low temperature, respectively. The image quality of the camera meets the requirements of the index despite degrading.

Numerical and Experimental Analysis of Light-Weighted Primary Mirror for Cassegrain Telescope

2011 ◽  
Vol 52-54 ◽  
pp. 59-64 ◽  
Author(s):  
Yu Chuan Lin ◽  
Long Jeng Lee ◽  
Shenq Tsong Chang ◽  
Yu Cheng Cheng ◽  
Ting Ming Huang
Keyword(s):  
Finite Element ◽  
Surface Deformation ◽  
Optical Design ◽  
Mechanical Analysis ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Primary Mirror ◽  
Numerical Result ◽  
Cassegrain Telescope ◽  
The Impact

This article reports an approach of light-weighted mirror design and analysis to increase the weight reduction ratio and improve optical performance based on the finite element method and opto-mechanical analysis. The approach is to represent mirror surface deformation derived from finite element analysis (FEA) by Zernike polynomials, such that the impact of deformation on optical system performance can be evaluated by the optical design and analysis program. The experimental modal analysis was also performed to validate the FEA results. The numerical result shows that the light-weighted primary mirror of Cassegrain telescope is obtained by this approach and predicted deformation fulfills the requirements of optical design.

A Study on the Adhesive Effects on the Optical Performance of the Primary Mirror System of a Satellite Camera

2007 ◽  
Vol 51 (6) ◽  
pp. 1901 ◽  
Author(s):  
Yu-Deok Seo ◽  
Hyun-Jung Kim ◽  
Sung-Kie Youn ◽  
Seung-Hoon Lee ◽  
Deog-Gyu Lee ◽  
...  
Keyword(s):  
Mirror System ◽  
Optical Performance ◽  
Primary Mirror

Finite Element Analysis for Surface Shape Deformation of Photo-Electronic Theodolite Primary Mirror

2008 ◽  
Vol 28 (4) ◽  
pp. 756-763 ◽  
Author(s):  
谭凡教 Tan Fanjiao ◽  
乔彦峰 Qiao Yanfeng ◽  
李耀彬 Li Yaobin ◽  
高慧斌 Gao Huibin ◽  
刘旨春 Liu Zhichun
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Surface Shape ◽  
Shape Deformation ◽  
Element Analysis ◽  
Primary Mirror

SOFIA primary mirror assembly: structural properties and optical performance

2003 ◽  
Author(s):  
Hermann Bittner ◽  
Matthias Erdmann ◽  
Peter Haberler ◽  
Karl-Heinz Zuknik
Keyword(s):  
Structural Properties ◽  
Optical Performance ◽  
Primary Mirror

Finite Element Analysis of the Effect of Particle Shape on the Thermal Conductivity in Diamond/Cu Composites

2014 ◽  
Vol 788 ◽  
pp. 689-692
Author(s):  
Hong Guo ◽  
Yuan Yuan Han ◽  
Xi Min Zhang ◽  
Fa Zhang Yin ◽  
Ye Ming Fan ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Thermal Resistance ◽  
Particle Shape ◽  
Finite Element Calculation ◽  
Element Calculation ◽  
Element Analysis ◽  
Result Show

The effect of diamond shape on the thermal conductivity of diamond/Cu composites was studied by combine finite element method with the tests. The finite element result show that the thermal conductivity of the hexoctahedron diamond/Cu composites and the square diamond/Cu composites is 819 W/m·K and 1013 W/m·K respectively. And the testing results indicate that the thermal conductivity of the single hexoctahedron diamond/Cu composites and the hexoctahedron mixed with the square diamond/Cu composites is 659W/m·K and 720 W/m·K respectively. The testing results consist with the finite element calculation. Under the same circumstances, more {100} faces can bring in less overall thermal resistance in the composites thus improve the thermal conductivity of the composites. The results show that using square diamond particles helps to improve the thermal conductivity of diamond/Cu composites.

Impact of Frame Positioning Errors on Fuselage Panel Assembly Variation

2013 ◽  
Vol 433-435 ◽  
pp. 847-851
Author(s):  
Wei Miao Yan ◽  
Yun Bo Bi ◽  
Xin Tian Fan ◽  
Kun Peng Du ◽  
Wei Wang
Keyword(s):  
Finite Element ◽  
Information Matrix ◽  
Principal Component ◽  
Element Model ◽  
Position Errors ◽  
Positioning Errors ◽  
Influence Coefficients ◽  
Assembly Accuracy ◽  
Optimum Selection ◽  
The Impact

This paper firstly establishes a finite element model of a fuselage panel, and then an assembly variation model is derived from the method of influence coefficients (MIC) and principal component analysis (PCA). With the calculation of Fisher information matrix and effective independence (EFI), 49 measurement points are extracted from a number of finite element nodes by the optimum selection method, and the mathematical relation between the position errors of measurement points and the positioning errors of frames is established, which is utilized to analyze the impact of positioning errors of each frame on fuselage panel assembly variation. Finally, the key frame that is important to ensure assembly accuracy and to improve the assembly process is determined.

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