• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文会议>ASME pressure vessels and piping conference;PVP2009 >CRACK GROWTH UNDER THERMAL FATIGUE LOADING (EFFECT OF STRESS GRADIENT AND RELAXATION)
【24h】

CRACK GROWTH UNDER THERMAL FATIGUE LOADING (EFFECT OF STRESS GRADIENT AND RELAXATION)

机译：热疲劳载荷下的裂纹扩展（应力梯度和松弛的影响）

获取原文
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Thermal fatigue is a critical problem in nuclear power plants. To prevent crack initiation, JSME has issued a guideline for design. In this study, the feasibility of incorporating crack growth analysis into the design and integrity evaluation was investigated. Two characteristics of thermal fatigue loading were considered. The first was the effects of stress gradient in the depth direction. It was shown that the steep stress gradient near the surface significantly reduced the stress intensity factor (SIF) of deep cracks. Assuming that crack growth is arrested by small SIF, it is possible to leave detected cracks unrepaired. Otherwise, the cracks should be removed regardless of their size. The other characteristic is the displacement controlled boundary condition. Through finite element analyses, it was revealed that the displacement controlled boundary condition reduces SIF, and the magnitude of the reduction in SIF depends on the crack depth and boundary length. It is concluded that, under thermal fatigue loading, the cracks that are detected in the in-service inspection have already been arrested if they do not penetrate the wall thickness. The crack arrest scenario is a reasonable method of assessing the integrity of cracked components.
机译：热疲劳是核电站中的关键问题。为了防止裂纹的产生，JSME发布了设计指南。在这项研究中，研究了将裂纹扩展分析纳入设计和完整性评估的可行性。考虑了热疲劳载荷的两个特征。首先是深度方向应力梯度的影响。结果表明，表面附近陡峭的应力梯度显着降低了深裂缝的应力强度因子（SIF）。假设小SIF阻止了裂纹扩展，则可以不对检测到的裂纹进行修复。否则，无论大小如何都应清除裂缝。另一个特征是位移控制的边界条件。通过有限元分析，揭示了受位移控制的边界条件减小了SIF，而SIF减小的幅度取决于裂纹深度和边界长度。结论是，在热疲劳载荷下，如果在役检查中发现的裂纹没有穿透壁厚，则该裂纹已经被阻止。止裂方案是评估破裂组件完整性的合理方法。

著录项

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