Fretting induced high cycle fatigue (HCF) is a primary failure mechanism in both aircraft engine and structural components. Fretting at the edge of the contact surface of titanium alloy turbine engine blade dovetails and disk posts is a well documented cause of catastrophic engine fatigue failure.  Surface enhancement by shot peening to introduce beneficial residual compression, and reduction of the coefficient of friction with anti-fretting coatings, are both beneficial, but do not eliminate the potential for failure. In aluminum aircraft structures, fretting at the fastener holes is a common source of fatigue crack initiation.  Interference-fit fasteners provide benefit, but may not eliminate fretting initiation or fatigue crack propagation. Low plasticity burnishing (LPB) has been demonstrated to provide a depth and magnitude of residual compression sufficient to prevent propagation of the shear initiated micro cracks found at the edge of contact of the fretting zone, completely mitigating fretting damage.

The theoretical basis for fretting induced micro crack arrest is reviewed in terms of both linear elastic fracture mechanics and the Fatigue Design Diagram (FDD) method.  The depth and magnitude of compression needed to mitigate fretting induced damage are developed using the FDD approach.  Fatigue bench test results comparing the benefits of low plasticity burnishing and conventional shot peening in mitigating fretting induced fatigue in Ti-6Al-4V are briefly reviewed. Extension of the LPB fretting mitigation technology from the F402 blades previously reported to the current F404 engine platform is described. Recent bench test results of the effects of LPB and shot peening on the fretting fatigue performance of aluminum-on-aluminum and steel-on-aluminum is presented for AA2024-T351. Results of fatigue testing are presented showing LPB mitigation of fastener induced fretting in low-load-transfer fastener fatigue specimens. The benefits of LPB induced compression in aluminum structural components are described in terms of the FDD approach.