Foreign Object Damage Of Blades And Its Influence On Fatigue Life

Damage of blade often occurs when objects such as bird and sand are ingested into aeroengine with the high speed airflow during motion of aeroengine. This kind of damage is called Foreign object damage or simply, FOD. The main form of foreign object damage are notch, avulsion, disjunction and indentation in local regions where produce stress concentration, residual stress , shear bands as well as .The vicinity of notch appears initial crack, which severely influences the lifetime of the damage blades. Therefor, the investigation for the mechanism of FOD and its influence on fatigue lifetime have important significance.The objective of the investigation for FOD is reviewing the dynamical response of blade which is undergone impacted by foreign object, ascertaining the extent of damage connecting with apiece parameter. Ago, investigating means often use experiment on model to simulate foreign object damage and its effect to fatigue lifetime of blade, mensurate remainder fatigue lifetime, but fatigue experiment itself has localization and the cost is high. Along with the development of the finite element method, numerical simulation has been paid attention to more and more in FOD. Combining numerical simulation with experiment is a kind of development for the study of FOD.This paper discusses three kinds of typical cases for different parts of blade undergone impact by small and hard grain. Three models are introduced to simulate the bedrock of the blade , the body of the blade and the leading edge of the blade respectively. This study reviews the elastic-plastic dynamical response to impact of Ti-6Al-4V, investigates the effect of the dimension , velocity and the shape of the impact object by using ANSYS. There is no shear bands in this study because the limited velocity. The numerical result indicates that, 1 , the impact time due to the stiff of the object undergone impact, it is microsecond when impact happening on the bedrock of the blade, it is millisecond when impact happening on the body of the...