Reverse educing method to estimate the blade's vibration stress under rotating state

A new method - reverse educing method is put forward in this paper, which is to estimate the vibration stress of aeroengine blade under rotating state. Based on the fracture mechanics theory, the vibration stress intensity factor K_v of the blade can be worked out by the 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 be calculated out finally. The results is very significant for trouble diagnosing and shooting of aeroengine blades.