(a) Indicate whether the following statements are True or False:

i.

A strain gauge can be used to measure shear strain.

ii.

The state of strain at a point can be determined by bonding 3 strain gauges.

iii.

Plane stress always result in Plane strain.

iv.

The shear strain is given by the equation, ? = ?/?, where ? = shear strain, ? =

shear stress and ? = modulus of rigidity.

(2 marks)

(b) A strain rosette, shown in Figure Q2 is attached on the outer surface of a mechanical

component. The strain readings are as follows:

?! = 600? ,

?" = 120?,

?# = 80?

Given ? = 200???, ? = 80 ??? and ? = 0.25 . At the location where the strain

gauges are attached, determine:

i.

The state of strain ?$, ?%, ?$% and sketch the corresponding strain element.

(2 marks)

ii.

The principal strains and sketch the corresponding strain element.

(2 marks)

iii.

The state of stress ?$, ?%, ?$% and sketch the corresponding stress element.

(2 marks)

iv.

The principal stress and sketch the corresponding strain element.

(2 marks)