杨平,彭子牙,姜伟,余志锋,胡康.低周疲劳下考虑累积塑性应变的裂纹板裂纹闭合效应研究[J].,2018,58(4):371-378 |
低周疲劳下考虑累积塑性应变的裂纹板裂纹闭合效应研究 |
Research on crack closure effect for cracked plate under low cycle fatigue considering accumulative plastic strain |
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DOI:10.7511/dllgxb201804006 |
中文关键词:裂纹闭合效应低周疲劳累积塑性应变裂纹闭合参数裂纹板 |
英文关键词:crack closure effectlow cycle fatigueaccumulative plastic straincrack closure parametercracked plate |
基金项目:国家自然科学基金资助项目(51479153). |
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中文摘要: |
裂纹闭合效应发生在裂纹扩展过程中,影响着裂纹扩展速率,同时在裂纹尖端附近区域塑性应变的累积对诱发裂纹闭合效应以及结构破坏起着重大作用.为了研究裂纹扩展中复杂的闭合机理,以试验与数值模拟为基础,考察了裂纹闭合效应及其与累积塑性应变的关系,着重探究了应力比、循环次数、裂纹长度等相关因素的影响.研究结果表明,裂纹闭合水平与累积塑性应变及形成的塑性尾迹区之间存在着交互式的影响,且裂尖塑性应变的演化与尾迹区残余压应力场的关系能很好地反映裂纹闭合水平的变化过程,这为进一步研究低周疲劳裂纹闭合效应的复杂机理提供了新的途径. |
英文摘要: |
The crack closure effect occurs during the crack propagation and affects the crack propagation rate, while the accumulation of plastic strain near the crack tip plays a significant role in inducing crack closure and structural failure. In order to study the complex closure mechanism in crack propagation, the relationship between crack closure effect and accumulative plastic strain is studied based on experimental research and numerical simulation, and the influence of stress ratio, cycle number and crack length are emphatically investigated. The results show that there is an interactive effect between the crack closure level, the accumulative plastic strain and the formed plastic wake zone, and the relationship between the plastic strain at the crack tip and the residual compressive stress field in the wake zone can well reflect the crack closure level, which provides a new way to further study the complex mechanism of crack closure effect under low cycle fatigue. |
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