Test of 6-inch-thick pressure vessels. Series 1: intermediate test vessels V-1 and V-2

Test of 6-in. -thick pressure vessels. Series 3: intermediate test vessel V-7. [PWR and BWR]

“…50 Based presumably on the fact that the yield stress in the near inside surface ligament considerably exceeds the yield stress of the midthiil'Jiess material and on the appearance of previous fracture surfaces examined. 13 it was predicted (by an unspecified method) that failure would occur by rapid crack extension at an internal pressure of 159 MPa (23 ksi). The propagating crack was expected to arrest before reaching the circumferential welds, but a leak without rupture failure was not expected.…”

“…which was considerabiy less than the actual failure pressure of 16S MPa (23.9 ksi). A posttest local plastic instability analysis of model V7E-A3, based on the conventional assumption of a trapezoidal effective load-bearing area 13. resulted in a calculated pressure of 134 MPa (19.5 ksi).…”

Test of 6-inch-thick pressure vessels. Series 2. Intermediate test vessels V-3, V-4, and V-6

“…Nevertheless, as discussed in Ref. 5, a prediction of the failure strain for intermediate test vessel V-2 was made by the tangent modulus method, using the modified Irwin >5 k . correction, assuming that the occurrence of plastic strain in the direction 262 normal to the crack plane would cause a decrease in transverse restraint and a consequent increase in fracture toughness.…”