Approximate method of elastic--plastic fracture analysis for nozzle corner cracks

Conference · Sat Jan 01 04:00:00 EST 1977

OSTI ID:5381501

Merkle, J. G.

Two intermediate test vessels with inside nozzle corner cracks have been pressurized to failure at ORNL by the HSST Program. Vessel V-5 leaked without fracturing at 88/sup 0/C (190/sup 0/F), and Vessel V-9 failed by fast fracture at 24/sup 0/C (75/sup 0/F) as expected. The nozzle corner failure strains were 6.5 and 8.4 percent, both considerably greater than pretest plane strain estimates. The inside nozzle corner tangential strains were negative, implying transverse contraction along the crack front. Therefore, both vessels were reanalyzed, considering the effects of partial transverse restraint by means of the Irwin ..beta../sub Ic/ formula. In addition, it was found possible to accurately estimate the nozzle corner pressure-strain curve by either of two semiempirical equations, both of which agree with the elastic and fully plastic behavior of the vessels. Calculations of failure strain and fracture toughness corresponding to the measured final strain and flaw size are made for both vessels, and the results agree well with the measured values.

• Research Organization: Oak Ridge National Lab., Tenn. (USA)
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5381501
• Report Number(s): CONF-771140--2
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220200* -- Nuclear Reactor Technology-- Components & Accessories
CALCULATION METHODS
CONTAINERS
CRACKS
DESTRUCTIVE TESTING
FATIGUE
FRACTURE PROPERTIES
MATERIALS TESTING
MECHANICAL PROPERTIES
MECHANICAL TESTS
NOZZLES
POWER REACTORS
PRESSURE VESSELS
REACTORS
STRESS ANALYSIS
TESTING