2015 EJRNL PP Chen Bao 1.pdf
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Terbatas Irwan Sofiyan
» ITB
Terbatas Irwan Sofiyan
» ITB
This study successfully deals with the inhomogeneous dimension problem of load
separation assumption, which is the theoretical basis of the normalization method. According to
the dimensionless load separation principle, the normalization method has been improved by introducing
a forcible blunting correction. With the improved normalization method, the J-resistance
curves of five different metallic materials of CT and SEB specimens are estimated. The forcible
blunting correction of initial crack size plays an important role in the J-resistance curve estimation,
which is closely related to the strain hardening level of material. The higher level of strain
hardening leads to a greater difference in JQ determined by different slopes of the blunting line.
If the blunting line coefficient recommended by ASTM E1820-11 is used in the improved normalization
method, it will lead to greater fracture resistance than that processed by the blunting
line coefficient recommended by ISO 12135-2002. Therefore, the influence of the blunting line on
the determination of JQ must be taken into full account in the fracture toughness assessment of
metallic materials.