The figure shows a vertical bar A B C which is pinned at B and supported by horizontal rods at A and C. The length of the segments A B and B C are 400 millimeters and 520 millimeters respectively. The rod at C is of length 2000 millimeters and the rod at A is of length 1250 millimeters. A load P directed to the right acts on the bar between B and C.

For an axial member, normal strain is defined as the change in member length δ divided by the initial member length L:

ε=δL

Using this definition, the axial elongation corresponding to the measured +910 με strain can be computed for rod (1):

δ1=ε1L1   =(+910 με)1 mm/mm1×106με(2,000 mm)   =+1.82 mm