Project Crane - Group E

As told in the previous post, the material chosen is Aluminum 7075 due to various properties discussed before but now I will show a brief comparison of it with Steel and other form of aluminum.

Aluminum 7075	Steel
Specific Density 2.81g/cc	Specific Density 7.80g/cc
Price 0.93US$/lb	Price 0.59US$/lb
Ultimate Tensile Stress 275MPa	Ultimate Tensile Stress 558MPa
Young’s Modulus 72GPa	Young’s Modulus 190GPa

As seen from the table, the Young`s Modulus of Steel is very high than Aluminum 7075. But apart from this, it is very much lighter than Steel and due to this, it is suitable to be used in emergency situations.

Aluminum 7075	Aluminum 6061
Specific Density 2.81g/cc	Specific Density 2.75g/cc
Price 0.93US$/lb	Price 0.88US$/lb
Yield Strength 146MPa	Yield Strength 62 MPa
Young’s Modulus 72GPa	Young’s Modulus 65GPa

As seen from the table, the Specific Density of Aluminum 6061 and price is less than Aluminum 7075 but the Yield Strength is very much lower of Aluminum 6061 so one cannot use it for the crane design.

Therefore, due to convenient price, high tensile stress and less density we decided to use Aluminum 7075-T6 as our final material.