landing gear alloy and composite analysis by david cobler
TRANSCRIPT
Landing Gear Alloy and Composite Analysis
By David Cobler
Problem
• The landing gear for the Lunar Lander Satcube must take up the minimum amount of space required and be as light as possible.
Solution
• Analyze various Alloys and Composites for a material that is very strong and light weight.– Aircraft grade Aluminum– Aluminum-Lithium Alloy 8090– Beryllium-Aluminum Alloy 363– Titanium Ti-6-2-4-2– Carbon-Epoxy
Comparison Criteria
• Material Properties– Focusing mainly on Yield Strength and Density
• Availability and Cost
Aircraft Aluminum
• Somewhat light weight• Low strength• Many suppliers• Cheap
Yield Strength
Modulus Of Elongation Density
11.0 ksi 10600 ksi 0.100 lb/in³
%Elongation @ Break
Poisson's Ratio
Shear Strength
20.00% 0.33 18000 psi
Aluminum-Lithium Alloy 8090
• Lighter than Aircraft Aluminum• Much stronger than Aircraft
Aluminum• Not Readily Available• Very Expensive
Yield Strength
Modulus Of Elongation Density
53.7 ksi 11200 ksi 0.0918 lb/in³
%Elongation @ Break
Poisson's Ratio
Shear Strength
7.00% 0.305 39200 psi
Beryllium-Aluminum Alloy 363
• Lightest Aluminum Alloy• Not as strong as Al-Li• Not Readily Available• Expensive• Permanent and or fatal
respiratory hazards when machining
Yield Strength
Modulus Of Elongation Density
30.990 ksi 29300 ksi 0.0780 lb/in³
%Elongation @ Break
Poisson's Ratio
Shear Strength
3.00% 0.2 35900 psi
Titanium Ti-6-2-4-2
• Not very light weight• Very strong• Specialty Suppliers• Somewhat Pricy
Yield Strength
Modulus Of Elongation Density
144.0 ksi 17,400 ksi 0.164 lb/in³
%Elongation @ Break
Poisson's Ratio
Shear Strength
3.00% 0.32 100,000 psi
Carbon-Epoxy Sheet
• Extremely light weight• Very strong• Specialty suppliers• Relatively Cheap
Yield Strength
Modulus Of Elongation Density
87.0 ksi 10200 ksi 0.0578 lb/in³
%Elongation @ Break
Poisson's Ratio
Shear Strength
0.80% None Found 13100 psi
Overall Comparison
Yield Strength11.0 ksi144000 psi87000 psi53700 psi30990 psi
Density0.100 lb/in³0.164 lb/in³0.0578 lb/in³0.0918 lb/in³0.0780 lb/in³
Yield Strength/Density110 ksi/(lb/in³)878 ksi/(lb/in³)1505 ksi/(lb/in³)584 ksi/(lb/in³)397 ksi/(lb/in³)
Aircraft AluminumTitanium Ti-6-2-4-2Carbon Fiber EpoxyAluminum Lithium alloy 8090Beryllium-aluminum
The Beryllium and Lithium Alloys are to expensive, unavailable, or warrant health risks that do not make them appropriate.
Aircraft Aluminum is the Cheapest material at about 15$ per ft^2Carbon-Epoxy was found around 65$ per ft^2Titanium was found to be much higher and ranging in prices.
Questions?