Experimental Aluminum Structures for Space Shuttle Applications

Discuss about the Analysis of Suitability of Aluminum Composites.

There is need for the use of light and cost-effective metals in space shuttles (Gibson, et al., 2014).  Over the years aluminum has been tested for this application since it is light and of moderate cost. This project deals with the fabrication of aluminum and performing of tests on it to check if it is suitable for application in space shuttles. The results from the fabrication and tests will be used to demonstrate that aluminum is suitable for application in space shuttle side panels for the mid fuselage, landing gear struts and wing carry-through panels. This project aims to prove that aluminum can perfectly fit in the manufacturing of space shuttles where weight and cost are put into perspective.  Other objectives will be:

• To fabricate tubes and test them
• To test the suitability of aluminum in application in space shuttle.
• To explore the construction of space shuttles and compare the various metals involved in their construction.

A couple of experimental aluminum structures have been developed for space shuttle applications. The successful testing of aluminum in space shuttle application has resulted to the use of aluminum on tubular struts on the mid-fuselage unit of the Space Shuttle Orbiter (William, et al., 2011). The use of boron/aluminum composites dates back to the time when it was used as a tube for the truss structure of a space shuttle in the 1970s (Anderson, et al., 2017). Since then aluminum composites have had numerous applications due to their suitable properties. 

Many studies have been conducted on the suitability of aluminum composites in the construction of space shuttles, the aim of these studies is to determine whether aluminum composites can be used in the place of the conventional organic matrix materials.

Prater in his study on the use of aluminum in space shuttle construction states that aluminum matrix composites have evolved over the years from boron aluminum, graphite fiber aluminum and continuous fiber composites to space shuttle tube truss and continuous fiber composites this has resulted to their extensive application in space shuttle construction (Prater, et al., 2014). Most of the studies on aluminum application lack details on how the aluminum composite should be improved to be more effective.

Robertson and Miller in their article published in the NASA website state that many experimental aluminum/boron structures have been successfully constructed for the purpose of space vehicle and aircraft applications. The authors confirm that aluminum/ boron structures have magnificently undergone static, corrosion, damage tolerance, thermal and fatigue experiments for the purpose of application in space shuttles (Miller, et al., 2011).

Suitability of Aluminum Composites in Space Shuttle Construction

There has been immense study on the use of metal matrix composites and organic matrix composites with near zero coefficient of thermal expansion and high specific stiffness on the construction of space shuttles. The study indicates that in the orbit near the earth a spacecraft encounters factors such as human-made debris and micrometeoroids and naturally occurring phenomena such as atomic oxygen, plasma, vacuum, ionizing radiation and thermal radiation (Van der zee, et al., 2009). In order to stand all these factors space shuttles must be lightweight and stable with high pointing accuracy. Composite materials with low thermal expansion coefficient and high specific stiffness provide the perfect properties to be used in the construction of these space shuttles.

However, the study on composite materials does not exhaustively show the testing and application of aluminum materials in the construction of space shuttles, they only highlight that aluminum composites have the required characteristics such as low thermal expansion coefficient and high specific stiffness.

Space shuttles are essential for space exploration, advances in the technology used in space shuttle have a significant effect on earth technology. The use of aluminum composites on space shuttles will reduce the cost of construction and make them lighter thus more effective. The application of these aluminum composites may spread to airplanes to achieve the same benefits. Fuel consumption will be significantly reduced since aluminum composites are light weight thus the space shuttle will need less fuel to move (Ono, et al., 2012). The Durability of the aluminum composites makes them suitable for space shuttle application since it will save the cost of replacements and building other space shuttles and since the aluminum composites have great corrosion resistance this will reduce the cost of replacing the space shuttle parts due to corrosion (Kasen, et al., 2013).

This project presents a unique pathway to enhance our understanding on the use of aluminum composites in space shuttles. There will be a detailed research on Metal-matrix composites (MMCs) with focus on aluminum composites. The aim of the project will be application of a metal with low coefficient of thermal expansion and high specific stiffness. Aluminum composites satisfy these requirements thus they will be tested for possible replacement of organic-matrix such as graphite/epoxy. This will ensure more space craft efficiency, cost effectiveness and less weight (Adebisi, et al., 2011). The use of aluminum composites will be enhanced by application in the space shuttle replacing the conventional organic matrix materials. This innovation will ensure that space shuttles are constructed by the use of materials which will reduce the cost of construction and make them lighter thus more effective and fuel conservative and will ensure the Durability of the space shuttles.

Properties of Composite Materials in Construction of Space Shuttles

This is the deterioration of a material in this case aluminum as a result of interaction with its environment. The indirect (e.g. delays, litigation, loss of productivity as a result of outages and failures) and direct cost of corrosion is extremely high, thus there is need to test any material meant for industrial application for corrosion. The following procedure is used for the aluminum corrosion test (Saninno, et al., 2009):

• Prepare “sandwich” with two metal couponsand a piece of filter paper soaked with MWF.
• Test is run with both MWF concentrate anddiluted mix.
• Conditions: 100o F for 8 hr and 100o F + 100%humidity for 16 hr – 7day duration.
• Coupons: 7075 T-6 clad aluminum and 7075 T-6 anodized, (2 in. x 4 in.)
• Sizes: Coupons 2 in. x 4 in., Paper 1 in. x 3 in.
• Compare to distilled water as control fluid.

The expected outcomes are as follows

Product	Strip immersion for 24 hours	Sandwich test (Boeing 12.3)
Synthetic	Clean	Conc Passed Mix Passed
Soluble oil A	Clean	Conc Passed Mix Failed
Soluble oil B	Clean	Conc Failed Mix Passed
Soluble oil C	Clean	Conc Failed Mix Failed

A static test of the aluminum composites will be tested using a 3D testing machine using the 3D method. The methods is implemented in that the 3D machine will scan the composites noting their layer thickness and hardness.

Damage of the aluminum composites will be tested using the 3D testing method above. Since the probability of damage depends on the hardness of the aluminum composites the higher the hardness level the lower the probability of damage (Kumar, et al., 2011).

The aluminum composites will be given a T6 heat treatment, then they will be artificially aged under various conditions after which they will be tested for mechanical fatigue.

The T6 heat treatment method will be applied, followed by aging of the composites under different conditions and tested for thermal fatigue, during the test for thermal fatigue focus is made on the changing of material properties such as stress strain curves for microscopic and macroscopic characteristics and hardness.

The outcome of this tests will demonstrate the suitability of aluminum composites for space shuttle application (Ibrahim, et al., 2014). 

After the successful testing of the aluminum composites the method of diffusion bonding will be used to manufacture the components such as plates, panels and tubes to be used in spacecrafts.

The following tests will be conducted on the aluminum composites corrosion, static, damage, tolerance, mechanical fatigue and thermal fatigue after which a thorough analysis will be conducted to ascertain the suitability of the composites to be applied in the construction of space shuttles. A 3D scanning machine will be used to scan the aluminum composites noting their layer thickness and hardness, this will be used to determine the static, damage and tolerance of the composites. The Boeing Spec. BAC 5008 – 12.3 Aluminum “Sandwich” Test method will be applied in the test for the corrosion of the aluminum composites. For thermal fatigue and mechanical fatigue aluminum composites will be given a T6 heat treatment, then they will be artificially aged under various conditions and tested (Ibrahim, et al., 2014). All these methods are aimed at determining the suitability of the aluminum composites for application in the construction of space shuttles. 

Corrosion Testing of Aluminum Composites

The expected outcomes are as follows from the corrosion test are shown in the experiment part above with the method used known as the Boeing Spec 12.3 (sandwich test)

This project will take a period of one month from the time of writing the project abstract and proposal to performing the various tests on the aluminum composites to determine their suitability to be applied in space shuttles.

The project Gantt chart is as shown below:

Project stage	June 15	June 20	June 25	July 8	July 9	July 10	July 11
Project Abstract
Project introduction
Research Proposal
Literature review
Methodology (Documenting the methods to be used for experimentation)
Ground Data Collection, experiments on aluminum composites (testing for corrosion, static, damage, tolerance, mechanical fatigue and thermal fatigue) and Documentation
Data analysis
Results
Discussions
Concluding remarks
References
Appendices
Executive Summary
Table of Contents

Ethical correctness and approval must be achieved in conducting a research. The researcher has to follow certain requirements in order to attain this. Before conducting the research, there will be an in-depth analysis of the dangers the fabrication of tubes and performing of tests on them may pose to those carrying out the experiment and the public (Botelho, et al., 2007).

All these precautions will be taken to ensure the safety of those involved in the experiment. All laboratory rules when using the labs will be followed to the letter to ensure safety.

• It will result in massive weight saving as opposed to conventional non-composite designs.
• The use of aluminum composites on space shuttle will help the concerned parties to save on cost as compared to other metals. This will save the government a significant amount of money which will be channeled to other sectors in the economy.
• Fuel consumption is significantly reduced since aluminum composites are light weight thus the space shuttle needs less fuel to move.
• Durability of the aluminum composites makes them suitable for space shuttle application since it will save the cost of replacements and building other space shuttles (Dvorak, 2008, 655-687).
• Remarkable corrosion resistance thus reduces the cost of replacing the space shuttle parts due to corrosion

References

Adebisi, A. A., M. A. Maleque, and M. M. Rahman. “Metal matrix composite brake rotor: historical development and product life cycle analysis.” International Journal of Automotive and Mechanical Engineering 4, no. 1 (2011): 471-480.

Kharkovsky, Sergey, and Reza Zoughi. “Microwave and millimeter wave nondestructive testing and evaluation-Overview and recent advances.” IEEE Instrumentation & Measurement Magazine 10, no. 2 (2007): 26-38.

De Volder, Michael FL, Sameh H. Tawfick, Ray H. Baughman, and A. John Hart. “Carbon nanotubes: present and future commercial applications.” science 339, no. 6119 (2013): 535-539.

Gibson, B. T., D. H. Lammlein, T. J. Prater, W. R. Longhurst, C. D. Cox, M. C. Ballun, K. J. Dharmaraj, G. E. Cook, and A. M. Strauss. “Friction stir welding: process, automation, and control.” Journal of Manufacturing Processes 16, no. 1 (2014): 56-73.

Van der Zee, Frank P., and Francisco J. Cervantes. “Impact and application of electron shuttles on the redox (bio) transformation of contaminants: a review.” Biotechnology advances 27, no. 3 (2009): 256-277.

Prater, Tracie. “Friction stir welding of metal matrix composites for use in aerospace structures.” Acta Astronautica 93 (2014): 366-373.

Ono, Kanji, and Antolino Gallego. “Research and applications of AE on advanced composites.” J. Acoust. Emiss 30 (2012): 180-229.

William F.. Smith, and Javad Hashemi. Foundations of materials science and engineering. McGraw-Hill, 2011.

Ibrahim, M. E. “Nondestructive evaluation of thick-section composites and sandwich structures: A review.” Composites Part A: Applied science and manufacturing 64 (2014): 36-48.

Anderson, Ted L. Fracture mechanics: fundamentals and applications. CRC press, 2017.

Sannino, A. P., and H. J. Rack. “Dry sliding wear of discontinuously reinforced aluminum composites: review and discussion.” Wear 189, no. 1-2 (2009): 1-19.

Kumar, GB Veeresh, C. S. P. Rao, and N. Selvaraj. “Mechanical and tribological behavior of particulate reinforced aluminum metal matrix composites–a review.” Journal of minerals and materials characterization and engineering 10, no. 01 (2011): 59.

Botelho, Edson Cocchieri, Rogério Almeida Silva, Luiz Cláudio Pardini, and Mirabel Cerqueira Rezende. “A review on the development and properties of continuous fiber/epoxy/aluminum hybrid composites for aircraft structures.” Materials Research 9, no. 3 (2007): 247-256.

Bakshi, Srinivasa R., and Arvind Agarwal. “An analysis of the factors affecting strengthening in carbon nanotube reinforced aluminum composites.” Carbon 49, no. 2 (2011): 533-544.

Dvorak, G. J., Y. A. Bahel-el-Din, Y. Macheret, and C. H. Liu. “An experimental study of elastic-plastic behavior of a fibrous boron-aluminum composite.” Journal of the Mechanics and Physics of Solids 36, no. 6 (2008): 655-687.

Rawal, Suraj P. “Metal-matrix composites for space applications.” Jom 53, no. 4 (2009): 14-17.

Kasen, M. B. “Mechanical and thermal properties of filamentary-reinforced structural composites at cryogenic temperatures 1: Glass-reinforced composites.” Cryogenics 15, no. 6 (2013): 327-349.