Some Considerations of the Influence of Sub-Critical Cleavage Growth during Fatigue-Crack Propagation in Steels
Some Considerations of the Influence of Sub-Critical Cleavage Growth during Fatigue-Crack Propagation in Steels
复制标题
钢疲劳裂纹扩展过程中亚临界解理生长影响的一些思考
DOI：
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发表时间：
1975
期刊：
影响因子：
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通讯作者：
BMet F. Knott
中科院分区：
文献类型：
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作者：
C. Beevers;R. J. Cooke;J. Knott;R. Ritchie;BMet F. Knott
结果表明，在中、高生长速率下，平均应力的影响是由“静态”模式的出现直接引起的。不稳定性附近速率的最终加速度被认为与这些模式的临界连接有关。在此阶段，将裂纹扩展速率与交变应力强度δK联系起来是不合适的，因为应力强度的最大值Kmax对于确定总裂纹前缘中有多少是由穿晶解理面组成以及裂纹扩展的速度是至关重要的。还讨论了疲劳过程中的终端应力强度与单调加载下的KIc值（断裂韧性）之间的差异。这种差异的一个可能的解释是提出在裂纹尖端的塑性诱导加热。
The results are interpreted in terms of a 3-stage relationship between log growth-rate and log δK, and show that, for intermediate and high growth-rates, effects of mean stress are caused directly by the occurrence of ‘static’ modes. The final acceleration in rate near instability is considered to be associated with the critical linkage of such modes. During this stage it is inappropriate to relate the crack growth-rate to the alternating stress intensity, δK, because the maximum value of stress intensity, Kmax, is critical in determining how much of the total crack front is composed of transgranular cleavage facets and hence how fast the crack is growing. Discussion is also included on the difference between the terminal stress intensity during fatigue and the K Ic value (fracture toughness) under monotonic loading. A possible explanation for such differences is proposed in terms of plasticity-induced heating at the crack tip.