Optimal Design of a Truss Structure for a Segmented Reflector

1995 ◽  
Author(s):  
Mark A. Hahn ◽  
Maj D. Mirmirani ◽  
Helen R. Boussalis
Keyword(s):  
Optimal Design ◽  
Modal Analysis ◽  
Pareto Optimality ◽  
Multicriteria Optimization ◽  
Truss Structure ◽  
Test Bed ◽  
Baseline Model ◽  
Large Space ◽  
Design Requirements

Abstract Design requirements for a support truss used in a segmented reflector telescope test-bed are identified. From these requirements a baseline model of the support truss is developed. Multicriteria optimization and Pareto optimality concepts are employed to obtain an optimal truss structure among variations of the baseline model that yields a correct balance between strength and flexibility. Modal analysis shows that the structure exhibits the characteristics of a large space-borne structure.

Skylab's Astronaut Maneuvering Unit (Experiment M509) — A Comparison of Six Degree of Freedom Simulation and on-Orbit Flight

1974 ◽  
Vol 18 (2) ◽  
pp. 187-187
Author(s):  
A. M. Ray
Keyword(s):  
Space Shuttle ◽  
Space Station ◽  
Degree Of Freedom ◽  
Test Bed ◽  
Control Logic ◽  
Test And Evaluation ◽  
Unit Design ◽  
Design Requirements ◽  
Experiment Hardware ◽  
Six Degree Of Freedom

A test bed type astronaut maneuvering unit was designed and evaluated with the assistance of Martin Marietta's six degree of freedom simulator. Four different control modes were developed for this unit for test and evaluation inside Skylab's 22 foot diameter orbital workshop. The orbital tests have provided the experience and technology base necessary for space Shuttle and space station astronaut maneuvering unit design requirements. This paper is an overview of the M509 experiment hardware, procedures, and results with emphasis on the comparison between on-orbit test results and the six degree of freedom simulator. The simulator was used to develop the unit's design requirements, evaluate the control logic parameters, and for developing maneuvers and training the crew. The simulator will also be flown by the Skylab crews in May for post flight evaluation and simulator calibration. (Films of the simulations and on-orbit flight are available as part of this presentation.)

An Insight into the Features of the OAO-C Thermal Design

1973 ◽  
Vol 95 (4) ◽  
pp. 1039-1047 ◽  
Author(s):  
H. Fine ◽  
J. Quadrini ◽  
S. Ollendorf
Keyword(s):  
Thermal Control ◽  
Astronomical Observatory ◽  
Thermal Design ◽  
Test Bed ◽  
Large Space ◽  
Flight Data ◽  
The Earth ◽  
Ground Test ◽  
Earth Observation Satellite ◽  
Insight Into

The Orbiting Astronomical Observatory (OAO)-C was successfully launched into 400-nautical mile circular orbit on August 21, 1972. For this spacecraft, a unique sensitivity approach to the thermal design was developed which resulted in a predictal design—the merits of which should be considered for application on future spacecra. The OAO-C is also serving as a test bed for the evaluation of thermal control hardware. To provide flight data for space program applications, experiments for a new coating and four different heat pipe designs are on this spacecraft. The data derived from OAO-C will be extremely valuable for such future programs as the Large Space Telescope (LST) and the Earth Observation Satellite (EOS). This paper will describe the detailed of the sensitivity design approach and thermal control hardware. For all aspects discussed, a comparison of pertinent analysis, ground test data, and flight data [1] will be given.

Design and Fabrication of an Affordable Transfemoral Prosthetic Leg

2016 ◽  
Vol 842 ◽  
pp. 435-444 ◽  
Author(s):  
Emilio O. Bachtiar ◽  
Tatacipta Dirgantara ◽  
Sandro Mihradi ◽  
Andi Isra Mahyuddin
Keyword(s):  
Optimal Design ◽  
Design Method ◽  
Body Part ◽  
Knee Joints ◽  
Prosthetic Limbs ◽  
Industry Standards ◽  
Final Design ◽  
Normal Human ◽  
Design Requirements ◽  
Analysis System

An invalid is a person with physical or mental abnormalities which hinders their ability of doing normal human activities. One of the aforementioned abnormalities is the loss or malfunction of a body part or organ, such as the human leg. Problems brought about by this disability could be alleviated by the use of prosthetic limbs to restore normal bodily functions [1]. While there are many needs for leg prosthetics in Indonesia, the price of commercially available prosthetic is prohibitively high for most amputees. The current available affordable prosthetics are very basic and employ monocentric knee joints. Here an attempt is made towards acquiring an optimal design of an affordable prosthetic leg using previously developed four-bar knee joint [2,3]. The design is carried out by implementing a systematic design method to arrive at an affordable, yet ones with better performances. The procedure involves a rubric and analyzing various alternatives to arrive at an optimal design conclusion. The evaluation objective is to maximize the performance of the leg and knee prosthetics through an extensive analysis with considerations from various stakeholders, including the potential users, fabricator, and hospitals in Indonesia [4]. The final design of the leg consists of a composite socket, an aluminum pylon, and a solid-ankle cushioned-heel foot design. Its components are modular and compatible with prosthetic industry standards. The knee is made of a combination of polymers and stainless steel and employs a polycentric mechanism in order to satisfy design requirements while keeping costs low [4,5]. The leg and knee were then fabricated according to the analysis results. The total cost of fabrication is approximately 5.5 million IDR, significantly cheaper than commercial prosthetics. The prototype is then tested and examined using a gait analysis system previously developed at Institut Teknologi Bandung by the Biomechanics Research Team [6]. The results show satisfactory performance, albeit with a host of potential improvements.

An Optimization Based Methodology to Design Flexible Systems Subjected to Changing Operating Conditions

2005 ◽  
Author(s):  
Ritesh A. Khire ◽  
Anoop A. Mullur ◽  
Achille Messac
Keyword(s):  
Optimal Design ◽  
System Design ◽  
High Performance ◽  
Systematic Approach ◽  
Operating Conditions ◽  
Flexible Systems ◽  
Operating Life ◽  
Design Requirements ◽  
High Performance Level ◽  
Critical Aspects

Flexible systems maintain a high performance level under changing operating conditions or design requirements. Flexible systems acquire this powerful feature by allowing critical aspects of their design con guration to change during the operating life of the product or system. In the design of such systems, designers are often required to make critical decisions regarding the exible and the non-exible aspects of the design con guration. We propose an optimization based methodology to design exible systems that allows a designer to effectively make such critical decisions. The proposed methodology judiciously generates candidate optimal design versions of the exible system. These design versions are evaluated using multiobjective techniques in terms of the level of exibility and the associated penalty. A highly exible system maintains optimal performance under changing operating conditions, but could result in increased cost and complexity of operation. The proposed methodology provides a systematic approach for incorporating designer preferences and selecting the most desirable design version — a feature absent in several recently proposed exible system design frameworks. The developments of this paper are demonstrated with the help of a exible three-bar-truss design example.

scholarly journals Operational Modal Analysis of the Laboratory Steel Truss Structure

2019 ◽  
Vol 40 ◽  
pp. 800-807
Author(s):  
Lukáš Maliar ◽  
Daniela Kuchárová ◽  
Ľuboš Daniel
Keyword(s):  
Modal Analysis ◽  
Operational Modal Analysis ◽  
Truss Structure ◽  
Steel Truss
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