Numerical modelling of microscopic lubricant flow in sheet metal forming. Application to plane strip drawing

Abstract

This paper presents a numerical investigation of microscopic lubricant flows from the cavities to the plateaus of the surface roughness of metal sheets during forming processes. This phenomenon, called micro-plasto-hydrodynamic (MPH) lubrication, was observed experimentally in various situations such as compression sliding tests, strip drawing and cold rolling. It leads to local friction drop and wear reduction. It is therefore critical to achieve a good understanding of this phenomenon.To move towards that goal, a multiscale fluid-structure interaction (FSI) model is developed to model lubricant flows at the microscopic scale. These simulations are made possible through the use of the Arbitrary Lagrangian Eulerian (ALE) formalism.In this paper, this methodology is used to study plane strip drawing. The numerical model is able to predict the onset of lubricant escape and the amount of lubricant flowing on the plateaus. Numerical results exhibit good agreement with experimental measurements.

A hybrid Lagrangian–Eulerian particle finite element method for free‐surface and fluid–structure interaction problems

“…As pointed out in Reference 26, a pure Lagrangian description of the problem would lead to displacements of the nodes at the top edge and the Lagrangian definition of the boundary would be lost. Although there exist other possibilities to treat this problem with a fully Lagrangian approach (see e.g., Reference 48), in this work nodes lying on the top edge are simply treated as Eulerian. Three different cases are considered, see Figure 8: (a) Lagrangian domain with Eulerian top boundary only ( LagDom , Figure 8A); (b) entire domain treated as Eulerian ( EulDom , Figure 8B); (c) hybrid domain with Lagrangian and Eulerian subdomains, with separating interface placed at the horizontal centerline ( HybDom , Figure 8C).…”

The Influence of Hydrostatic Pressure Build-Up on Asperity Flattening Under Bulk Plastic Deformation

“…Lo and Wilson (1999) presented a theoretical model to investigate the two effects. Carretta et al (2017a) performed a numerical study with a model (Carretta et al, 2017b) which matched the experimental results by Azushima et al to gain more insights into the fundamental mechanisms behind the phenomenon. In an analytical model for cold rolling in the mixed lubrication regime, Saniei and Salimi (2006) employed the average Reynolds equations, which were first introduced by Patir and Cheng (1977).…”