Question

12. In an experiment to determine the modulus of elasticity of a sample of mild steel, a wire is loaded and the corresponding extension noted. The results of the experiment are as shown. Draw the load/extension graph (verify your plot using appropriate software) Load (N) 0 40 110 160 200 250 290 340 Extension 0 1.2 3.3 4.8 6.0 7.5 10.0 16.2 (mm) The mean diameter of the wire is 1.3mm and its length is 8.0 m. Determine the

Answer 1

0 load (N) Extension 40 Ilo 160 200 750 0 1.2. 3.3 cmm) 4.8 6 7.5 slopa 33.33 33.33 33.33 33.33 33.33 2go 340 16.2 29 20.99 so elastic limit is 250N because upto that point load l extension slope is constant and curve is line 250 7.5 mm De Td 1, 3273 mm2 cross section area (A) = 8,6'm L 8000 mm

o= E E Ez al L at elastic limit limit or region 250 4 ala w 1.5 Sol ExL=6 A De 3) E- 250x dooo 1.3273 X 75 E=200, gog MPa Er 200, glupa --- Stress at elastic limit (oel Fe 250 MPa ve 11. 1,3273 A se = 188.35 MPal os