Affordable Compressor Blade Fatigue Life Extension Technology

"Improved damage tolerance is critical to achieving reduced engineownership costs and increasing safety and fleet readiness. InPhase I, low plasticity burnishing (LPB) was successfullydemonstrated to improve the damage tolerance of the F404 1ststage fan blade by an order of magnitude through the introductionof high magnitude through-thickness compressive residual stressin the FOD sensitive leading edge. The objective of this PhaseII research effort is to apply LPB to the F402 LPC-V1 trailingedge to immediately address an HCF safety related problem, andthen to address the engineering issues necessary to transitionLPB blade processing to the fleet. Reverse engineering methodswill be established to efficiently develop LPB processingparameters and CNC code for other components. Finite elementmethods will be used to optimize the LPB residual stress fieldsand to predict the fatigue performance benefit for other bladesand materials. The data necessary to predict fatigueperformance, including thermal and overload relaxation to supportlong-range life prediction, will be generated.LPB processing will find initial Phase III application in Navydepots to increase damage tolerance of fan and compressor bladesduring engine overhaul, reducing replacement, maintenance andinspection costs. The introduction of LPB as a manufacturingprocess by engine OEMs will follow to extend the performance,improve safety and reduce the cost of ownership of milit