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

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.

2010 ◽  
Vol 36 ◽  
pp. 80-85 ◽  
Author(s):  
Yu Chuan Lin ◽  
Long Jeng Lee ◽  
Shenq Tsong Chang ◽  
Yu Cheng Cheng ◽  
Ting Ming Huang

This article reports an accurate analysis approach of finite element modeling and optical modeling. It has been used for design and analysis of many opto-mechanical systems such as large telescopes and laser systems. 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 optical design and analysis program. The methodology of shell-based and solid-based finite element modeling and the comparison of their results have been described in this paper. The result shows that the deformation of the light-weighted mirror designed by this approach fulfills the requirements of optical design. The simulation results of shell based FE model are in good agreement with those of solid based FE model.


Author(s):  
Ning Yu ◽  
Andreas A. Polycarpou ◽  
Jorge V. Hanchi

Oblique impact of a slider with a rotating disk in hard disk drives was analyzed using the finite element method. A three dimensional, thermomechanical, impact model was developed to study the mechanical and thermal response during the impact of a spherical slider corner with the disk. The model was validated by comparing finite element results with analytical solutions for homogeneous glass disk under simple conditions. Impact penetration, stress and incurred flash temperature were obtained for various normal impact velocities.


2012 ◽  
Vol 590 ◽  
pp. 487-491
Author(s):  
Qin Man Fan

The frame is the main part of the force matrix of truck vehicle and the stress state is complex and difficult to design. The finite element method is more accurate for the analysis of the static and dynamic characteristics of the frame, which provide guidance for the frame structure design. Establish finite element model of the frame with the application of ANSYS. According to the mechanical analysis of the model, impose reasonable constraints and load, the most typical of the four conditions in the frame is calculated with the finite element analysis, and predicted the weak parts of the frame according to the frame stress-strain cloud, which provided a very important theoretical basis for the improvement of the frame structure of the frame and optimizing design of the frame.


2012 ◽  
Vol 433-440 ◽  
pp. 5896-5901
Author(s):  
Li Kun Guan ◽  
Xin Yu Zhang

Objective: To establish a finite element model for ladle turret’s supporting arm. Verify the accuracy of finite element analysis, and accurate information cause of crack. Methods: Use ANSYS finite element analysis software to perform a solution of the supporting arm at loaded full ladle . By mean of strain measuements ,impact coefficient was obtained,and presents an analytical study of static strength of the supporting arm. Result:The greater the load is, the smaller the impact factor is. Verify the accuracy of the finite element method by on-site response test. Accordingly, it improves the supporting arm on the structure by effective basis.


2013 ◽  
Vol 690-693 ◽  
pp. 1966-1971
Author(s):  
Peng Shang ◽  
Kai Cheng Qi ◽  
Ya Xu Wang ◽  
Yu Ming Guan

This paper used the finite element method to compare the mechanical properties of two different configuration counterweight booms of the bucket wheel stacker reclaimer. And two different forms of the finite element analysis model of the counterweight booms were built in ANSYS. The stresses and strains under its working state were calculated. Then the impact of the counterweight arm to the force and stability of the whole rack could be analyzed. The results of this analysis provided a basis to select different types of the counterweight booms in different environment, and it has an important guidance and reference significance to the design and analysis of counterweight booms of large-scale machinery.


2014 ◽  
Vol 1073-1076 ◽  
pp. 1729-1732
Author(s):  
Nian Nian Xi ◽  
Fu Guo Tong ◽  
Gang Liu ◽  
Tao Zhong

This paper is committed to analyze the results of numerical simulation in the dam foundation seepage field of Guxue concrete gravity dam with the finite element method. The results show that the cutoff wall depth of the Guxue dam foundation seriously impacts the seepage effect of cutoff wall. The cutoff wall initially becomes deeper, the reduction of seepage discharge is distinct to reach 24%, as the depth increases gradually, the seepage discharge reduces slowly and can only reach 7%. In a word, the cutoff wall depth of Guxue concrete gravity dam exists a reasonable value and the numerical result is15m in this paper.


1990 ◽  
Vol 18 (4) ◽  
pp. 216-235 ◽  
Author(s):  
J. De Eskinazi ◽  
K. Ishihara ◽  
H. Volk ◽  
T. C. Warholic

Abstract The paper describes the intention of the authors to determine whether it is possible to predict relative belt edge endurance for radial passenger car tires using the finite element method. Three groups of tires with different belt edge configurations were tested on a fleet test in an attempt to validate predictions from the finite element results. A two-dimensional, axisymmetric finite element analysis was first used to determine if the results from such an analysis, with emphasis on the shear deformations between the belts, could be used to predict a relative ranking for belt edge endurance. It is shown that such an analysis can lead to erroneous conclusions. A three-dimensional analysis in which tires are modeled under free rotation and static vertical loading was performed next. This approach resulted in an improvement in the quality of the correlations. The differences in the predicted values of various stress analysis parameters for the three belt edge configurations are studied and their implication on predicting belt edge endurance is discussed.


1998 ◽  
Vol 26 (2) ◽  
pp. 109-119 ◽  
Author(s):  
M. Koishi ◽  
K. Kabe ◽  
M. Shiratori

Abstract The finite element method has been used widely in tire engineering. Most tire simulations using the finite element method are static analyses, because tires are very complex nonlinear structures. Recently, transient phenomena have been studied with explicit finite element analysis codes. In this paper, the authors demonstrate the feasibility of tire cornering simulation using an explicit finite element code, PAM-SHOCK. First, we propose the cornering simulation using the explicit finite element analysis code. To demonstrate the efficiency of the proposed simulation, computed cornering forces for a 175SR14 tire are compared with experimental results from an MTS Flat-Trac Tire Test System. The computed cornering forces agree well with experimental results. After that, parametric studies are conducted by using the proposed simulation.


2015 ◽  
Vol 12 (19) ◽  
pp. 5871-5883 ◽  
Author(s):  
L. A. Melbourne ◽  
J. Griffin ◽  
D. N. Schmidt ◽  
E. J. Rayfield

Abstract. Coralline algae are important habitat formers found on all rocky shores. While the impact of future ocean acidification on the physiological performance of the species has been well studied, little research has focused on potential changes in structural integrity in response to climate change. A previous study using 2-D Finite Element Analysis (FEA) suggested increased vulnerability to fracture (by wave action or boring) in algae grown under high CO2 conditions. To assess how realistically 2-D simplified models represent structural performance, a series of increasingly biologically accurate 3-D FE models that represent different aspects of coralline algal growth were developed. Simplified geometric 3-D models of the genus Lithothamnion were compared to models created from computed tomography (CT) scan data of the same genus. The biologically accurate model and the simplified geometric model representing individual cells had similar average stresses and stress distributions, emphasising the importance of the cell walls in dissipating the stress throughout the structure. In contrast models without the accurate representation of the cell geometry resulted in larger stress and strain results. Our more complex 3-D model reiterated the potential of climate change to diminish the structural integrity of the organism. This suggests that under future environmental conditions the weakening of the coralline algal skeleton along with increased external pressures (wave and bioerosion) may negatively influence the ability for coralline algae to maintain a habitat able to sustain high levels of biodiversity.


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