The correlation between the fracture characteristics values evaluated from the tear test and the fracture toughness values were investigated. New method to evaluate the fracture toughness was examined by the tear test. The correlation between the fracture characteristics (σ
in,
UIEt and
UPEt), which were newly defined based on the true crack initiation point in the tear test and the fracture toughness values (
KIC,
JIC and
Tmat) evaluated by the ASTM E-399 method was studied, and a good correlation was recognized between σ
in and
KIC,
UIEt and
JIC, and
UPEt and
Tmat, respectively. The critical stress intensity factor (
KC) obtained from the precracked tear test agree well with
KIC values evaluated by the ASTM E-399 method. However,
KC obtained from the standard tear test is overestimated about 20% comparing with the
KIC because of the effect of the notch tip radius.
抄録全体を表示