Log s

.82.8^ 2 x 1902 = 850 x 106[logi,(r/82.8) - 0.405] and <7ge = 850 x 106tloge(r/82.8) + 0.595]

.-. At the bore surface where r = 62.5 mm the stresses due to autofrettage are: orr = -580 MN/m2 and om = 266.7 MN/m2.

Residual stresses are then obtained by elastic unloading of the autofrettage pressure, i.e. by applying orr = +580 MN/m2 at the bore in eqns (10.5) and (10.6)^; i.e. by proportions:

, 580 , arr = 580 MN/m2 and am = -298.3 x -= -721 MN/m2.

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