首页> 外文期刊>Journal of the Mechanics and Physics of Solids >Atomistic origin of size effects in fatigue behavior of metallic glasses
【24h】

Atomistic origin of size effects in fatigue behavior of metallic glasses

机译:金属玻璃疲劳行为中尺寸效应的原子起源

获取原文
获取原文并翻译 | 示例
           

摘要

While many experiments and simulations on metallic glasses (MGs) have focused on their tensile ductility under monotonic loading, the fatigue mechanisms of MGs under cyclic loading still remain largely elusive. Here we perform molecular dynamics (MD) and finite element simulations of tension-compression fatigue tests in MGs to elucidate their fatigue mechanisms with focus on the sample size effect. Shear band (SB) thickening is found to be the inherent fatigue mechanism for nanoscale MGs. The difference in fatigue mechanisms between macroscopic and nanoscale MGs originates from whether the SB forms partially or fully through the cross-section of the specimen. Furthermore, a qualitative investigation of the sample size effect suggests that small sample size increases the fatigue life while large sample size promotes cyclic softening and necking. Our observations on the size-dependent fatigue behavior can be rationalized by the Gurson model and the concept of surface tension of the nanovoids. The present study sheds light on the fatigue mechanisms of MGs and can be useful in interpreting previous experimental results.
机译:尽管对金属玻璃(MGs)进行的许多实验和模拟都集中在单调载荷下的拉伸延展性,但在循环载荷下,MGs的疲劳机理仍然难以捉摸。在这里,我们在MG中执行分子动力学(MD)和拉伸压缩疲劳测试的有限元模拟,以阐明其疲劳机理,重点是样本量效应。发现剪切带(SB)的增厚是纳米级MG固有的疲劳机理。宏观和纳米级MG之间的疲劳机理差异源自SB是通过试样横截面部分形成还是全部形成。此外,对样本量影响的定性研究表明,小样本量会增加疲劳寿命,而大样本量会促进循环软化和颈缩。我们对尺寸依赖的疲劳行为的观察可以通过Gurson模型和纳米空隙的表面张力概念来合理化。本研究阐明了MGs的疲劳机制,可用于解释以前的实验结果。

著录项

  • 来源
  • 作者单位

    International Center for Applied Mechanics, State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi'an Jiaotong University, Xi'an, China;

    Institute of High Performance Computing, A*STAR, Singapore;

    Institute of High Performance Computing, A*STAR, Singapore;

    Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, 3651 Watt Way, VHE 611, Los Angeles, CA, United States;

    International Center for Applied Mechanics, State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi'an Jiaotong University, Xi'an, China;

    State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace Engineering, Xi'an Jiaotong University, Xi'an, China;

    Institute of High Performance Computing, A*STAR, Singapore;

    School of Engineering, Brown University, Providence, RI, United States;

  • 收录信息 美国《科学引文索引》(SCI);美国《工程索引》(EI);
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

    Fatigue mechanism; Finite element modeling; Metallic glasses; Molecular dynamics simulations;

    机译:疲劳机制有限元建模;金属玻璃;分子动力学模拟;

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号