Question

3-5. The stress-strain diagram for a steel alloy having an original diameter of 12 mm and a gauge length of 50 mm is given in the figure. If the specimen is loaded until it is stressed to 500 MPa, determine the approximate amount of elastic recovery and the increase in the gauge length after it is unloaded. O (MPa) 600 - E(mm/mm) 0 0 0.04 0.08 0.12 0.16 0.20 0.24 0.28 0.0005 0.001 0.0015 0.002 0.0025 0.003 0.0035 Prob. 3-5

Answer 1

Que - 3-5. The stress - Strain diagram for a steel alloy having an original diameter of 12 mm and gauge length of somm is given in Fig. It the specimen is loaded until it is stressed to Soo MPa. Determine the approximate amount of elastic recovery and the increase in the gouge length after it is unloaded. 6(MPa) Ans. Given Data's original - 10 =12mm Diameter 600 5DD gauge length = somm 400 300 (L) 290 TOO from the stress 200 Strain diagram 100 The Modulus of clasticity for the o o steed alloy is Where o Das 04 0.08 0.12 10.16 0.20 6.24 0.28 € (mm ) 0.001 D OIS D'OD2 0-0098 0.003 cod f iq. 000172 Stress - strain Diagram) Elaste Recovery I is the stress at the propostional limit is the strain at the proportional limit. E- 5 E 290 0.001 E = 290x103 MPa Page 1/2

line when the Specimen is uploaded, It's normal strain recoved along which has a gradient of E 500 500 Elastic Recovery = = 290x103 = 0.00172 mm/min Elastic Recovery = 0.00172 mmImm Thus, the permanent set is, &p= 0.04 -0.00172 Ep = 0.0382 mm/mm Then, the increase in gauge length is Ep = ALL AL = Ep x L = 0.0382 x 50 OL = 1.914 mm Page 2/2