Engineering Rock Mechanics

Strain analysis 41 7

Note that strains are dimensionless.

Transformation of displacement (plane strain)
Say point P moves to P' when deformation takes place. If we know u and
v, can we calculate u' and v' on the new axes x'y' in terms of e?

'#\ 't P'

I U

P

U' = u cos0 + v sin0

V' = v cos0 - u sin0

Transformation of strain (plane strain)

Given E,, 5 and yq (i.e. global components) how do we calculate E:, E; and

y& (the local components)?