Based on air gun method

the foreign object damage (FOD) simulation test of stainless steel plate specimen was carried out. The macroscopic characteristics of damage were observed by three-dimensional numerical microscope

whilst the microscopic characteristics of damage were observed by scanning electron microscope. It was found that

the macro damage characteristics include compressional deformation

material shear loss

plastic deformation

etc.

and the micro damage characteristics of damaged specimens involve micro cracks

plastic deformation

micro notches and lamellar structure

etc. By step loading test method

the high cycle fatigue test was made on FOD specimen. The test results show that the fatigue strength of FOD specimen deceases over 14% compared with non-damaged specimen. Fatigue strength decreases with the increasing damage size. The origin of the fatigue cracks lies in micro cracks or micro notches

indicating that FOD provides favorable conditions for fatigue crack initiation and growth.