Branching and Propagation Behaviors of Fatigue Crack in Precracked Specimen.
Branching and Propagation Behaviors of Fatigue Crack in Precracked Specimen.
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预裂试样中疲劳裂纹的分支和扩展行为。
DOI：
10.2472/jsms.50.1329
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
D. Socie
中科院分区：
文献类型：
--
作者：
C. Makabe;D. Socie
研究了预裂纹钢在有轴向静应力和无轴向静应力的循环扭转载荷下裂纹的扩展行为。剪切模式裂纹扩展后，在裂纹两侧观察到裂纹分支。分支点之间的长度取决于加载条件。当施加的剪切振幅和静态轴向应力水平较高时，该长度较长。裂纹扩展曲线存在转折点。在转折点之前，观察到剪切型裂纹扩展，并且裂纹扩展速率与分支行为具有良好的相关性。结果表明，裂纹的张开和微裂纹的萌生有助于剪切型裂纹的扩展。裂纹分叉后，加载方式由循环扭转改为推拉加载。当外加正应力较大时，裂纹在最大剪应力准则下扩展。当外加应力较低时，裂纹在最大主应力条件下扩展。这些行为也与滑移带密度和裂纹张开度有关。
The growth behavior of crack was investigated under cyclic torsion with and without axial static stress using pre-cracked steel. After shear mode crack growth, branching of the crack was observed on both sides of the crack. The length between the branching points was dependent on loading conditions. This length was longer when the applied shear amplitude and the static axial stress level were higher. The crack propagation curves have turning points. Before the turning point, shear mode crack growth was observed and the crack propagation rate had good correlation with the branching behavior. It is found that the crack opening and the initiation of micro cracks help the shear mode crack growth After the branching of crack, loading method was changed from cyclic torsion to push-pull. When applied normal stress was higher, the crack grew under the condition of maximum shear stress criterion. On the other hand, when applied stress was lower, the crack grew under the condition of maximum principal stress criterion. Those behaviors are also related to slip band density and crack opening.