航空学报 > 2001, Vol. 22 Issue (4): 303-307

旋转状态下叶片振动应力的断口反推法

李海燕1, 张学仁1, 阎晓军1, 聂景旭1, 陶春虎2   

  1. 1. 北京航空航天大学动力系405 教研室, 北京 100083;2. 北京航空材料研究院, 北京 100095
  • 收稿日期:2000-06-19 修回日期:2000-08-31 出版日期:2001-08-25 发布日期:2001-08-25

REVERSE EDUCING METHOD TO ESTIMATE THE BLADE'S VIBRATION STRESS UNDER ROTATING STATE

LI Hai-yan1, ZHANG Xue-ren1, YAN Xiao-jun1, NIE Jing-xu1, TAO Chun-hu2   

  1. 1. Department of Jet Propulsion, Beijing University of Aeronautics and Astronautics, Beijing 100083, China;2. Beijing Institute of Aeronautic Material, Beijing 100095, China
  • Received:2000-06-19 Revised:2000-08-31 Online:2001-08-25 Published:2001-08-25

摘要:

提出了一种确定航空发动机叶片振动应力的新方法——断口反推法。该方法依据断裂力学的基本原理,从叶片实际断口测得裂纹疲劳扩展速率 da/d N值,并利用材料的裂纹扩展速率 da/d N同裂纹应力强度因子幅值 ΔK之间的关系,确定出叶片在振动应力作用下的振动应力强度因子;然后采用有限元数值计算方法对叶片进行静力分析、模态分析及裂纹应力强度因子计算,最后反推出叶片在旋转状态下振动应力值的大小。该方法根据叶片的实际断口情况计算出叶片在断裂之前的振动应力值,对于叶片的故障分析及故障排除将具有重要的意义。

关键词: 叶片, 振动应力, 应力强度因子, 有限元法

Abstract:

A new method - reverse educing method is put forward in t his paper, which is to estimate the vibration stress of aeroengine blade un der rotating state. Based on the fracture mechanics theory, the vibration stress intensity factor K v of the blade can be worked out by t he value of crack's growth ratio da/dN, which is gotten from the actual fracture section, and the relationship between da/dN and the stress intensity factor amplitude ΔK. Through static, modal and crack stress intensity factor analysis, the vibration stress of blade under rotating state before fracture can b e calculated out finally. The results will be very significant for trouble diagnosing and shooting of aeroengine blades.

Key words: blade, vibrat ion stress, stress intensity factor, finite element analysis method