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| 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 for Cracked Plate under Low Cycle Fatigue Considering Accumulative Plastic Strain |
| 投稿时间：2018-01-22 修订日期：2018-04-08 |
| DOI： |
| 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 low cycle fatigue accumulative plastic strain crack closure parameter cracked plate |
| 基金项目:国家自然科学基金项目（面上项目-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,而同时在裂纹尖端附近区域的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,文章以数值模拟与实验研究为基础,研究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 complicated closure mechanism in crack propagation, the paper studies the relationship between crack closure effect and accumulative plastic strain based on experimental research and numerical simulation, and emphatically investigates the influence of stress ratio, cycle number and crack length. The results show that there is an interactive effect between the crack closure level and the accumulated plastic strain and the formed plastic wake, the relationship between the plastic strain at the crack tip and the residual compressive stress field in the wake region 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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