scholarly journals Fatigue. Unified Description of Small Crack Growth Rate Using .DELTA.CTOD in Both HCF and LCF Conditions.

1997 ◽  
Vol 46 (10) ◽  
pp. 1173-1177
Author(s):  
Masahiro MIYAKE ◽  
Shoji HARADA ◽  
Yosihito KUROSIMA ◽  
Masao TAKAHARA
Keyword(s):  
Growth Rate ◽  
Crack Growth Rate ◽  
Crack Growth ◽  
Small Crack ◽  
Small Crack Growth ◽  
Unified Description

scholarly journals Relation Between Scatter in Crack Growth Rate and Small Crack Growth Law.

1994 ◽  
Vol 43 (494) ◽  
pp. 1469-1474
Author(s):  
Masahiro GOTO ◽  
Norio KAWAGOISHI ◽  
Hironobu NISITANI ◽  
Hiroomi MIYAGAWA ◽  
Yasuji ODA
Keyword(s):  
Growth Rate ◽  
Crack Growth Rate ◽  
Crack Growth ◽  
Small Crack ◽  
Small Crack Growth

Surface Small Crack Growth Behavior of Type 304 Stainless Steel in Low-Cycle Fatigue at Elevated Temperature

1988 ◽  
Vol 110 (1) ◽  
pp. 9-16 ◽  
Author(s):  
Masakazu Okazaki ◽  
Tomohiro Endoh ◽  
Takashi Koizumi
Keyword(s):  
Growth Rate ◽  
Grain Size ◽  
Crack Growth Rate ◽  
Grain Boundaries ◽  
Crack Growth ◽  
Low Cycle Fatigue ◽  
Small Crack ◽  
Average Grain Size ◽  
Small Crack Growth ◽  
Macroscopic Crack

Surface small crack growth behavior of Type 304 stainless steel during low cycle fatigue under fast-fast and slow-fast cyclings was investigated at a temperature of 873 K by using the smooth specimens which had the different grain sizes. It was shown that the crack, which had already grown up to a few grain size, predominantly propagated with strain cycling, and that it was very important for the safety assessment of the components in service to detect the crack of a few grain sizes. It was also shown that small crack growth rate showed the minimum when they arrived at the grain boundaries. Above behavior resulted from that the grain boundaries temporarily impeded the small crack growth. The crack length below which the grain boundaries notably affected the small crack growth rate was also given as the function of relative length to the average grain size. Furthermore, the small crack growth rate was compared with the macroscopic crack growth one. In fast-fast cycling, the small crack growth rate was about ten times as large as the macroscopic crack growth one, where its length was comparable to the grain size. Based on the results thus obtained, the application limit of macroscopic crack growth law to the surface small crack growth was discussed. The application limit proportionally increased with the grain size, and it was about ten times average grain size in both fast-fast and slow-fast cyclings.

The Variation of Crack Energy Density (CED) on Creep Crack Growth

2007 ◽  
Vol 353-358 ◽  
pp. 106-109
Author(s):  
C.S. Jeong ◽  
Byeung Gun Nam ◽  
Katsuhiko Watanabe
Keyword(s):  
Growth Rate ◽  
Crack Growth Rate ◽  
Energy Density ◽  
Crack Growth ◽  
Early Stage ◽  
Creep Crack Growth ◽  
Creep Crack ◽  
Crack Behavior ◽  
Creep Crack Growth Rate ◽  
Unified Description

Creep crack growth (CCG) rate has been organized frequently by C* or Ct parameter However, crack behavior of early stage under unsteady state condition has not been explained. Crack energy density (CED), which has been proposed as a parameter that can provide a unified description of crack behavior with no restriction on constitutive equation, can give the general expression about creep crack growth rate. By applying Ct and the concept of CED to the results, we showed that creep crack growth rate for all ranges of creep can be explained in a unified way by CED and its derivatives. Moreover, the physical meaning of the Ct is clarified in the discussion.

SMALL CRACK GROWTH BEHAVIOR AND EVALUATION OF GROWTH RATE OF COPPER PROCESSED BY EQUAL CHANNEL ANGULAR PRESSING

2012 ◽  
Vol 06 ◽  
pp. 245-250
Author(s):  
KUSNO KAMIL ◽  
MASAHIRO GOTO ◽  
SEUNG-ZEON HAN ◽  
KWANGJUN EUH ◽  
NORIO KAWAGOISHI ◽  
...  
Keyword(s):  
Growth Rate ◽  
Crack Growth Rate ◽  
Crack Growth ◽  
Plastic Zone Size ◽  
Growth Behavior ◽  
Small Crack ◽  
Stress Intensity Factor Range ◽  
Crack Growth Behavior ◽  
Angular Pressing ◽  
Average Grain Size

Ultrafine grained copper processed by 4 cycles of equal angular pressing was fatigued to study the growth behavior of a small crack. After the crack initiation, the behavior of a major crack was monitored through plastic replication technique, showing that the crack growth rate is proportional to the crack length regardless of stress amplitudes. The crack growth rate of major cracks was evaluated by a term σanl, not by the stress intensity factor range, ΔK. Analysis on fracture surfaces by scanning electron microscopy showed a planar followed by a striated surface. The formation mechanism of fracture surface morphologies was discussed by considering the average grain size and the reversible plastic zone size at a crack tip.

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