Experimental and Numerical Investigations of Fretting Fatigue Behavior for Steel Q235 Single-Lap Bolted Joints

Abstract EN

This work aims to investigate the fretting fatigue life and failure mode of steel Q235B plates in single-lap bolted joints.

Ten specimens were prepared and tested to fit the S-N curve.

SEM (scanning electron microscope) was then employed to observe fatigue crack surfaces and identify crack initiation, crack propagation, and transient fracture zones.

Moreover, a FEM model was established to simulate the stress and displacement fields.

The normal contact stress, tangential contact stress, and relative slipping displacement at the critical fretting zone were used to calculate FFD values and assess fretting fatigue crack initiation sites, which were in good agreement with SEM observations.

Experimental results confirmed the fretting fatigue failure mode for these specimens.

It was found that the crack initiation resulted from wear regions at the contact surfaces between plates, and fretting fatigue cracks occurred at a certain distance away from hole edges.

The proposed FFD- N relationship is an alternative approach to evaluate fretting fatigue life of steel plates in bolted joints.