Materials vocabulary sheet 2 for chapter 4

Question 1

Define strain.

Answer 1

Strain is defined as the change of length per unit length. Strain is a ratio so there’s no unit. Stress causes strain.Putting pressure on an object causes it to stretch. Strain is a measure of how much an object is being stretched.

Question 2

What is the equation for strain?

Answer 2

Extension
————– = Stress
Length

Question 3

Define Young modulus(E).

Answer 3

When a material undergoes stress provided the limit of proportionality is not exceeded, the value of stress divided by strain is constant, this value is known as the young modulus of elasticity of the material.

Question 4

Equation for Young modulus(E)

Answer 4

Stress
E= ————–
Strain

Question 5

What does elastic mean?

Answer 5

The young modulus is constant.

Question 6

What is meant by yield?

Answer 6

The point at which the metal passes its elastic limit and starts becoming deformed.

Question 7

What is UTS?

Answer 7

Ultimate tensile strength is the maximum stress a material can withstand while being stretched or pulled before failing or break.

Question 8

Define yield strength.

Answer 8

The stress at which an elastic material under increasing stress ceases to behave elastically

Question 9

Define stiffness.

Answer 9

Stiffness is the measure of the difficulty of stretching or bending an object.