Fretting fatigue simulation for aluminium alloy using cohesive zone law approach

• Fretting fatigue model was developed using a bi-linear cycle-dependent cohesive zone law.
• Bending fretting fatigue tests were conducted with a dog-bone type specimen and flat-and-rounded pads.
• Stress amplitude–number of cycles to failure curves were determined from the simulation and the test.
• Good agreement between the calculated S–N curve and the measured one was obtained.

This paper describes high-cycle fretting fatigue modelling for 7050-T7451 aluminium alloy using a cohesive zone law. For the sake of crack generation arising from cyclic bending, a bilinear, cycle-dependent cohesive zone law is used including stiffness degradation and reduction of fracture energy with respect to fatigue cycles. The reduction rate of fracture energy is determined with experimental data. Implicit analysis is employed with commercial finite element software. Additionally, bending fretting experiments are performed with unnotched specimens and flat-and-rounded pads. Imposed stress amplitude (S)–number of cycles to failure (N) curves are determined after fretting fatigue tests. Direct comparison between simulation and experimental S–N curves is performed; maximum error is found to be 20% at the 5×104th cycle. It is demonstrated that a proposed method allows simulating fretting fatigue and predicting fretting life of aluminium alloys.