Structural Design of Primary Mirror Subassembly for Space Telescope

2013 ◽  
Vol 300-301 ◽  
pp. 903-906
Author(s):  
Hong Xu
Keyword(s):  
Structural Design ◽  
Material Selection ◽  
Thermal Characteristics ◽  
The Finite Element Method ◽  
Location Selection ◽  
Primary Mirror ◽  
Gravity Load ◽  
Lightweight Structure ◽  
Method Analysis ◽  
Surface Figure

In order to design a large aperture primary mirror with the diameter of 1150 mm, the parameters impacting on gravity deformation of the mirror were analyzed and discussed in detail, including material selection, diameter-thickness ratio, the number of the support points, location selection and lightweight structure, etc. A novel space mirror structure system was put forward, and its back was opened and supported by six points on back. The dynamic and static and thermal characteristics were analyzed based on the finite element method. Analysis results showed the surface figure accuracy reached to RMS 14.5nm under the action of gravity load along the optical axis direction and the first-order natural frequency was 214Hz which met to the designed indexes requirements.

Stress Variation in the Orthodontic Tipping Phenomenon Analysis through the finite element method

2018 ◽  
Vol 69 (8) ◽  
pp. 1992-1995
Author(s):  
Dan Dragos Sita ◽  
Ligia Brezeanu ◽  
Cristina Bica ◽  
Dana Manuc ◽  
Edwin Sever Bechir ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Alveolar Bone ◽  
Complex Structure ◽  
External Action ◽  
The Finite Element Method ◽  
Stress Variation ◽  
Orthodontic Bracket ◽  
Method Analysis ◽  
Element Method

The purpose of the study is to assess through a FEM (Finite Element Method analysis), the behavior of a complex structure (enamel-tooth-alveolar bone-periodontal ligament-pulp), subjected to an external load through an orthodontic bracket-with forces of various intensities and to determine its influence on the entire structure.It is necessary to analyze the way all elements of the structure take over the external action given by the action of an orthodontic appliance through the brackets and the influence on the inner component -the pulp-inside of which there are the nerve endings.

scholarly journals Development of Material Combination Model Considering Economics and Construction Efficiency for G-SEED Certification

2021 ◽  
Vol 13 (6) ◽  
pp. 3535
Author(s):  
Byung-Ju Jeon ◽  
Byung-Soo Kim
Keyword(s):  
Structural Design ◽  
Material Selection ◽  
Selection Model ◽  
Construction Costs ◽  
Seed Certification ◽  
Evaluation Scores ◽  
The Cost ◽  
Material Information ◽  
Business As Usual ◽  
Construction Efficiency

The Korean government proposed a goal to reduce its greenhouse gas emissions by 37% compared to business-as-usual levels by 2030 and launched the Green Standard for Energy and Environmental Design (G-SEED) certification system. The certification requires meeting the required score and material selection with a secured economy and construction efficiency. However, most buildings only focus on obtaining the certification scores instead of choosing economical materials with high construction efficiency. This research focused on developing a material selection model that considers both the construction efficiency and economy of the materials and the acquisition of material and resource evaluation scores from the G-SEED certification. This research, therefore, analyzed actual data to automate the material selection and compare alternatives to using a genetic algorithm to obtain optimized alternatives. This model proposes an alternative to constructability and economy when the required score and material information is entered. When the model was applied to actual cases, the result revealed a reduction in construction costs of about 37% compared to the cost with the traditional methods. The material selection model from this research can benefit construction project owners in terms of cost reduction, designers in terms of structural design time, and constructors in terms of construction efficiency

Knowledge-Based System for Supporting the Design of a Plate-Press

2012 ◽  
Vol 12 (2) ◽  
Author(s):  
David Potočnik ◽  
Miran Ulbin ◽  
Bojan Dolšak
Keyword(s):  
Material Selection ◽  
Compressive Load ◽  
The Finite Element Method ◽  
Design Quality ◽  
Suitable Material ◽  
Improve Design ◽  
Knowledge Based System ◽  
Cad System ◽  
Design Time ◽  
Knowledge Based

This paper presents a knowledge-based system capable of giving the designer quality support when making decisions from the aspect of modeling the reinforcement of a plate-press within a position of maximum compressive load, and by choosing suitable material for the plate. Based on the selected combination of reinforcement and material, this system acquaints the user with the size and position of the largest comparative stress, and the greatest nodal displacement in the load-direction. This system operates based on the implemented knowledge of experts in the execution of design, material selection, and numerical analysis based on the finite-element method (FEM), which was written with the help of parameters within the knowledge-base of the CATIA V5 CAD-system. Using this system gives the user an opportunity to reach conclusions that are crucial for designing a plate-press or pressure-loaded die-elements, in general. The results reveal that the system can dramatically shorten design time and improve design quality in comparison to manual design process.

Structural design optimization of space gravitational wave telescope primary mirror system

2020 ◽  
Vol 49 (7) ◽  
pp. 20190469
Author(s):  
王辰忠 Chenzhong Wang ◽  
胡中文 Zhongwen Hu ◽  
陈忆 Yi Chen ◽  
许明明 Mingming Xu ◽  
陈力斯 Lisi Chen
Keyword(s):  
Gravitational Wave ◽  
Design Optimization ◽  
Structural Design ◽  
Mirror System ◽  
Primary Mirror ◽  
Structural Design Optimization

scholarly journals Study on the Damping Effect of Particle Dampers considering Different Surface Properties

2019 ◽  
Vol 2019 ◽  
pp. 1-16
Author(s):  
Xiaowei Li ◽  
Yue Yang ◽  
Weixing Shi
Keyword(s):  
Energy Dissipation ◽  
Surface Property ◽  
Material Selection ◽  
Great Influence ◽  
Contact Theory ◽  
Theoretic Model ◽  
The Finite Element Method ◽  
Particle Damping ◽  
Vibration Experiment ◽  
Particle Dampers

Particle dampers are nonlinear vibration control devices. The surface property has a great influence on the performance of the particle damper, but it is difficult to be considered and analyzed. This paper firstly gives a view of how to establish a theoretic model of the particle damper. The dynamic equation and energy dissipation coefficient of collision are revised from the Hertz contact theory in the proposed theoretic model, considering the friction of particles. Then, a contrastive collision model relying on the finite element method is established to verify the reasonability of the theoretic model. The effects of different factors which will have an influence on the performance of the particle damper are discussed, and several conclusions on how to optimize the particle damper are proposed. Except for the aforementioned dynamic analysis, this paper also presents a particle damping index to evaluate the capability of energy dissipation of different materials, in order to facilitate the material selection in the practical design. Finally, an experiment is developed to verify the character of the collision and energy dissipation. The feasibility of the proposed method to estimate the surface property of different particles is validated by the free vibration experiment.

Influence of honeycomb dimensions and forming methods on the compressive properties of beetle elytron plates

2017 ◽  
Vol 22 (1) ◽  
pp. 28-39 ◽  
Author(s):  
Xiaoming Zhang ◽  
Jinxiang Chen ◽  
Yoji Okabe ◽  
Peiwei Zhang ◽  
Xiaobing Xiong ◽  
...  
Keyword(s):  
Structural Design ◽  
High Strength ◽  
Absorption Capacity ◽  
The Finite Element Method ◽  
Compressive Properties ◽  
Performance Requirements ◽  
Deformation Modes ◽  
Biomimetic Structures ◽  
Preparation Techniques ◽  
Forming Methods

For developing lightweight and high-strength biomimetic sandwich structures, this study investigates the influence of honeycomb dimensions and forming methods on the mechanical properties of beetle elytron plates relative to honeycomb plates via compression experiments and the finite element method. The results indicate that the trabecular-honeycomb core structure in beetle elytron plates can increase the compressive strength by approximately 50% and double the energy absorption capacity of honeycomb plates with the same material costs. Furthermore, the influence of three types of forming methods on the compressive properties of beetle elytron plates is investigated by comparing the different deformation modes of these structures with those of honeycomb plates. Based on these findings, application recommendations regarding the forming methods of beetle elytron plates are presented to facilitate the structural design and preparation techniques according to the performance requirements of different fields, which will accelerate the industrial application of these biomimetic structures.

scholarly journals Structural And Thermal Characteristics of Aluminum Grades 6063 and 7075 with Application of Nano Coatings

2018 ◽  
Vol 7 (2.32) ◽  
pp. 187
Author(s):  
Ch Sridhar Yesaswi ◽  
N Venkata Sai ◽  
K Vivek ◽  
B Raju ◽  
G Venkat
Keyword(s):  
Heat Exchangers ◽  
Power Plants ◽  
Material Selection ◽  
Structural Characteristics ◽  
Thermal Characteristics ◽  
Vital Role ◽  
Nano Particles ◽  
Technology Advancement ◽  
Nano Coating ◽  
Metal Pipes

To fabricate any product, material selection is one of the major constraints for many engineers even on today. An intensive research is being done by scientists and engineers over the properties and characteristics of the materials. Due to the technology advancement, applications of various new products are entering into market with different materials. From the past few decades composites and alloy materials are playing a vital role because of their unique nature. In the present work heat exchangers are taken into application. In nuclear and power plants heat exchangers plays a crucial role in cooling the reactors. When these are made to cool with water by sending through metal pipes over a period of time, metal pipes get easily corroded because of water and thermal conductivity of the metal. When base metals are coated with Nano-particles there is a drastic change in their behavior. In this paper Aluminum grade 6063 and grade 7075 are considered and coated with Al2O3-NaOH Nano fluids. Their thermal and structural characteristics are identified before and after Nano coating.    

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.

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