Testing of an unnotched AISI 4340 steel specimen gave the data shown in the tables below for various mean stresses (first table is for zero mean stress). (a) Fit the data to an equation of the form Oar = ANP with Oar given by Walker relationship in terms of R. Obtain values of the three constants A, B and y. (b) On a log-log graph of Oar vs. Nf, plot both the data points and your fitted line (c) Comment on the success of the fit 0a, MPa 948 834 703 631 579 524 Nf, cycles 222 992 6004 14 130 43 860 132 150 0q, MPa Om, MPa Ni, cycles 0a, MPa Om, MPa 414 310 379 345 276 552 207 483 621 621 621 414 414 414 517 Nf, cycles 445020 45 490 109 680 510 250 208 030 193 220 901 430 73 780 83 810 567 590 31 280 50490 84 420 437 170 730 570 414 207 207 -207 -207 -207 586 552 414 345 414 483 345 414 Testing of an unnotched AISI 4340 steel specimen gave the data shown in the tables below for various mean stresses (first table is for zero mean stress). (a) Fit the data to an equation of the form Oar = ANP with Oar given by Walker relationship in terms of R. Obtain values of the three constants A, B and y. (b) On a log-log graph of Oar vs. Nf, plot both the data points and your fitted line (c) Comment on the success of the fit 0a, MPa 948 834 703 631 579 524 Nf, cycles 222 992 6004 14 130 43 860 132 150 0q, MPa Om, MPa Ni, cycles 0a, MPa Om, MPa 414 310 379 345 276 552 207 483 621 621 621 414 414 414 517 Nf, cycles 445020 45 490 109 680 510 250 208 030 193 220 901 430 73 780 83 810 567 590 31 280 50490 84 420 437 170 730 570 414 207 207 -207 -207 -207 586 552 414 345 414 483 345 414