Assessment of lubrication and zinc coating on the high cycle fretting fatigue behaviour of high strength steel wires

The fatigue resistance of spiral strands used in civil engineering structures is related to the inter-wire fretting fatigue conditions. In order to get a better understanding of the damage mechanisms, fretting fatigue tests up to 107 cycles were carried out. The testing conditions were representative of the contact conditions in spiral strands undergoing free bending deformations at the anchorage and deflection devices. This paper focuses on the assessment of the effectiveness of lubrication and zinc coating in high cycle fretting fatigue conditions related to the partial slip regime with relative amplitude of displacement below 10 ?m. The experimental results have shown evidence of a dramatic increase in the fretting fatigue limit which reached about twice the experimental value determined for bright wires. Moreover, contrary to obvious expectation, the monitoring of the tangential contact force during the fretting fatigue tests have not shown any lower amplitude of the friction load values after over 50,000 cycles. Some progress in contact mechanics based on elastoplastic finite element modelling and simulations which take into account the anisotropy of the material are reported.

Author(s): L. Dieng, J.R. Urvoy, D. Siegert, P. Brevet, V. Perier and C. Tessier