It is known that fracture characteristics are changed due to the geometric configuration.
Also, it is known that toughness data obtained from the standard specimen test are conservative to
predict fracture behavior of the real piping. Thus fracture behavior by tests of pipes would to be
applied to the integrity evaluation for the piping system. However, fracture test with real pipe is not
only difficult to perform but also very expensive, and requires lots of experience. So an estimation
method of pipe’s fracture behavior is necessary to solve this problem. The objective of this thesis is to
propose a method to estimate the fracture behavior of a pipe from the result of the standard specimen
fracture test. For this, fracture tests for standard specimens and pipes are conducted. The resultant
load - load-line displacement record of the standard specimen was transformed to that of a pipe by
load separation method. To begin with, the load versus load-line displacement curve of a standard
specimen extracted from a pipe is normalized by a geometry function of the CT specimen. Then this
normalized curve was converted to pipe’s load versus displacement curve by a geometry function of
pipe. To verify the constraint factor and the geometric function of pipe, finite element analyses were
performed. To demonstrate the proposed method, experimental results of pipes are compared with
predicted results. Calculated results from CT specimens are similar to experimental results of pipes.
Therefore the transformability from a CT specimen to a pipe by load separation method is proved.
Consequently the applicability of the proposed method was proved.
