C5 Mechanical properties

Question 1

4 type of mechanical properties

Answer 1

1. strength
2. hardness
3. ductility
4. stiffness

Question 2

how mechanical properties use to understand material

two type

Answer 2

1. deformation
2. break

Question 3

elobrate

deformation

3 types

Answer 3

1. elongation
2. compress
3. twist

Question 4

explain how

Metal response to external load

3 ways

Answer 4

1. stress & strain
2. elastic deformation
3. plastic deformation

Question 5

how

Stress & strain response to external load

4 ways

Answer 5

1. tension
2. compression
3. shear
4. torsion

Question 6

explain

Elastic deformation

Answer 6

-deformation is recoverable
-temporary deformation disappears after removal of the applied forces

Question 7

plastic deformation

Answer 7

-stays even after removal of the applied forces
-permanent deformation is irreversible

Question 8

explain

stress

Answer 8

• force acting per unit area over which the force is applied
• unit Pa @ Psi

Question 9

explain

Strain

Answer 9

• Change in dimension per unit lenght
• cm/cm

Question 10

what it does

Tensile

Answer 10

causing elongation

Question 11

what it does

compression

Answer 11

causing shortening

Question 12

in stress (y-axis) vs strain (x-axis) graf, what does slope mean

Answer 12

slope = Young modulus / modulus elasticity

Question 13

hooke’s law

used for elastic deform

Answer 13

• “When an object has a relatively small deformation, the size of the deformation is directly proportional to the deforming load or force.”
• Fₛ = kx

Question 14

in graph, where is the elastic limit

Answer 14

at the end of straight line

Question 15

in graph, where is the tensile strength

Answer 15

at the curve line, the highest point

Question 16

in graph, where is the breaking point

Answer 16

at the end point of the curve line