Evaluation of size effect on strain-controlled fatigue behavior of a quench and tempered rotor steel: Experimental and numerical study
Evaluation of size effect on strain-controlled fatigue behavior of a quench and tempered rotor steel: Experimental and numerical study
复制标题
DOI：
10.1016/j.msea.2018.08.073
复制
发表时间：
2018-09
期刊：
影响因子：
--
通讯作者：
Shun‐Peng Zhu;S. Foletti;S. Beretta
中科院分区：
文献类型：
--
作者：
Shun‐Peng Zhu;S. Foletti;S. Beretta
将最弱连接理论与疲劳裂纹扩展模型相结合，建立了30 NiCrMoV 12钢低周疲劳（LCF）区试样尺寸效应的力学-概率模型。特别是，试样尺寸对疲劳寿命的影响是量化的应变控制疲劳和裂纹扩展的实验。三种几何形状试样的复型试验结果表明，其疲劳寿命几乎都是由相互作用、相互结合的多表面裂纹组成的。然后建立了一个多表面断裂模拟的概率过程，将随机过程的裂纹形成，扩展和离散表面裂纹之间的合并。此外，表面损伤演化的评估阐述了统计物理的基础上，为不同的结构尺寸/体积，分析寿命分布和测试结果之间表现出良好的一致性。
Combining the weakest-link theory with fatigue crack growth modeling, this study presents a mechanical-probabilistic modeling of specimen size effect for 30NiCrMoV12 steel in a low cycle fatigue (LCF) regime. Particularly, the influence of specimen size on fatigue life is quantified by experiments in strain-controlled fatigue and crack propagation. Experimental results from replica tests with three geometrical specimens indicate that nearly all of its fatigue life consists of multiple surface cracking with mutual interactions and coalescences. A probabilistic procedure for multiple surface fracture simulation is then established by incorporating random processes of crack formation, propagation and coalescence between dispersed surface cracks. Moreover, an evaluation of surface damage evolution is elaborated based on statistical physics for different structural sizes/volumes, which showed good agreement between analytical life distributions and test results.