In order to design appropriate technics for solving foreign object damage (FOD) problem

a simulated-blade was designed according to aero-engine compressor blade size characteristics

then pre-treated by two laser shock strengthening processes

and impacted by air gun system. The effect rule and strengthening mechanism on fatigue performance were analyzed by high-cycle axial fatigue tests and stress field analysis. Test results indicated that fatigue strength of simulated-blade decreased from 51845 MPa to 29072 MPa subjected to foreign object damage. When pre-treated by laser shock peening with 5 J and 7 J

fatigue strength was improved to 34449 MPa and 37493 MPa

respectively. The introduction of high compressive residual stress field by laser shock peening greatly improved the local stress field distribution in the damage area

which not only significantly improved the fatigue strength of the simulated blade

but also increased the deviation of fatigue notch factor. With these two technics

the greater laser energy means the greater residual stress value and depth

helping to reduce more effectively the amplitude of the equivalent stress intensity factor in the crack propagation process

and bring about the greater increase of fatigue strength and fatigue notch factor deviation of the damaged simulated blade.