ASSIGNMENT 2

Name : AINUL NASEHAH IBRAHIM

MATRIC NO : A149024

1) Explain why 0.2 % is used to find offset yield strength.

Actually, the stress required to produce an offset (plastic deformation) amount of 0.2 percent is

generally used for the standard strength equivalent to the yield point, which is called “0.2%

offset yield strength” or “0.2% proof stress.” Both yield point and 0.2% offset yield strength are

often referred simply to as “yield strength” or “yield stress.”

2) Discuss the difference between the yield strength of an aluminium and a steel. Why?

Steels are generally 66% heavier than aluminum but specific strength, the ratio of strength to

density, is the property of interest for aircraft designers. From the experiment, we can verify

that yield strength of steel have more increase than aluminium. This is because of the

microstructure and arrangement of atom in this two elements. For steel, we know that it is very

hard, so the atom in this element is more closed-packed and hard to move from one point to

another. However, aluminium is one of element that always use in real life. This is because

aluminium has more corrosion resistance than steel. We also know that aluminium is less

toughness than steel because of microstructure of atom is very less closed-packed, so the atom

inside can move freely between them.