Introduction/Design Specifications for Aircraft
Stress & Strain
A square rod of 200 mm, 1.5 m long, is pulled apart with a force of
50,000 N, what are the stress and strain?
E = σ/ε
- First, stress equals load divided by area. Area is 0.2 x 0.2
- (units need to be in metres) 0.04 m2Metre
- Stress = 50,000/0.04 = 1,250,000 N/m2 1.25 MPa
- E = 210GPa
- Strain = stress/E = 1,250,000/210,000,000,000 = 0.0000050
- The Elastic limit of steel 600MPa, this will not fail.
- What load needed to reach yield?
- Ans 24,000,000 or 24MN
My question is how did he get the first dot ?
and how did they get the answer of 24,000,000