Rigid bar ABC is supported by three symmetricallypositioned

Rigid bar ABC is supported by three symmetrically-positioned vertical rods as shown. There is no strain in the vertical rods before load P is applied at B. After load P is applied, the normal strain in rods (2) is 1.150 micros. Determine the normal strain in rod (1) in units micros. Enter your answer (without units) in the text box.

Solution

Elongation of all the rods should be equal to keep the rigid bar symmetrical.

Elongation of rod 2 = Length of rod 2 * strain in rod 2 = 3800 * 1150 * 10^-6 = 4.37 mm.

So elongation of rod1 = 4.37 mm

Strain in rod 1 = Elongation of rod1/Length of rod 1 = 4.37/4900 = 891.8 micros