Research on fracture criterion has great significance in structural integrity evaluation and metal forming analysis However, research on elastic-plastic fracture strength has long been a bottleneck. In this paper, the Finite-element-analysis Aided Testing (FAT) method was used to obtain the accurate full-range effective constitutive relation up to failure of the 30Cr2Ni4MoV rotor steel and 3Cr13 stainless steel. Four typical structure failure tests of the specimens with different stress triaxiality were carried out, and their fracture thresholds and critical stress triaxiality were obtained using finite element analysis according to the full-range constitutive relations. The results show that there exists logarithmic law between the maximum stress triaxiality and the first principal stress thresholds as those representative volume elements with the triaxiality of the specimens reach their critical breaking state. According to the first principle stress envelope of crack tip and the logarithmic fracture criteria, the Ⅰ-type crack fracture toughness of 30Cr2Ni4MoV and 3Cr13 steel was predicted. A new method is proposed to predict the J-resistance curve of the material with the I-type crack fracture based on the mechanism of crack static growth. As an example, the J-resistance curve of 30Cr steel was predicted and discussed.
HAN Guangzhao
,
CAI Lixun
,
YAO Di
,
YU Simiao
. Fracture criterion and plane-strain fracture toughness of ductile materials[J]. ACTA AERONAUTICAET ASTRONAUTICA SINICA, 2018
, 39(8)
: 221852
-221852
.
DOI: 10.7527/S1000-6893.2018.21852
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