A Simplified Model of Surface Burnishing and Friction in Repeated Make-up Process of Premium Tubular Connections

We develop a simplified model to predict the frictional behaviour of the contact between the surfaces of a rotary shouldered thread connection in the make-up process of premium tubular connections as used in the oil pipeline business. A classic wear model is applied at the scale of the surface asperities to predict the evolution of friction between initially shot-peened surface and bronze plated surface in repeated sliding. Validation is provided by experimental measurements of surface roughness before and after sliding. An average friction model is developed by applying a friction factor model to the asperity contact areas and an Eyring shearing theory to the entrapped thin lubricant film. The predictions of the magnitude of friction over various sliding cycles are compared with measurements from physical tests.