Deformation of solids

Question 1

what is the limit of proportionality

Answer 1

up to a maximum load, the extension of an elastic material is proportional to the applied load

Question 2

what is hooke’s law

Answer 2

F=kx // extension is directly proportional to the applied load

Question 3

what is the elastic limit

Answer 3

the maximum load a specimen can experience and still return to its original length when deforming force is removed

Question 4

what is elastic deformation

Answer 4

material will return to original length after load is removed

Question 5

what is the yield point

Answer 5

beyond the elastic limit, the molecular structure is permanently changed as crystal planes slide across each other

Question 6

what is plastic deformation

Answer 6

material will not return to original length after load is removed; it is ‘plastic’

Question 7

what is stress

Answer 7

the applied force per unit area of cross section
σ=F/A

Question 8

what is strain

Answer 8

the ratio of the change in length to original length
ε=ΔL/L

Question 9

what is young modulus

Answer 9

within limit of proportionality, strain is directly proportional to stress.
E=σ/ε // E=Fl/Ax

Question 10

what is UTS

Answer 10

(ultimate tensile stress) is the maximum stress that can be applied without wire breaking

Question 11

what is strain energy

Answer 11

all the work done in stretching material is stored as potential energy
E=½kx²