Abstract
The contact between solids in metal-forming operations often involves temperature-dependent viscoplasticity of the workpiece. In order to estimate the real contact area in such contexts, both the topography and the deformation behaviour should be taken into account. In this work, a deterministic approach is used to represent asperities in appropriately shaped quadratic surfaces. Such geometries are implemented in indentation finite element simulations, in which the indented material has thermo-viscoplastic properties. By creating a database of simulation data, investigations in terms of contact load and area for the specifically shaped asperities allow for an analysis on the influence of the material properties on the load–area relation of the contact. The temperature and viscoplasticity greatly define how much load is supported by a substrate due to an indenting asperity, but the description of the deformation behaviour at small values of strain and strain rate is also relevant. The pile-up and sink-in regions are very dependent on the thermo-viscoplastic conditions and material model, which consequently affect the real contact area calculation. The interplay between carried load and contact area of a full surface analysis indicates the role that different sized asperities play in the contact under different thermomechanical conditions.
Highlights
The Finite Element (FE) simulations allowed us to build a database from which the influence of the thermo-viscoplastic behaviour of the deforming material in the load–area relation was investigated
The analysis is focused on four different aspects of the contact evaluated from the results database: the contact load, the average pressure supported by the substrate, the real contact area, and the displacement of the non-contacting area
An approach to calculate contact mechanics quantities such as load and area of a contact involving the indentation of a temperature-dependent viscoplastic material was presented
Summary
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Estimation of the real contact area between two contacting solids can be seen as an initial step towards investigating friction and wear of that contact, which are of uttermost interest in various engineering applications [1–10]. In the context of metalworking, bulk forming operations such as hot rolling of Al alloys are greatly dependent on the contact conditions: the real area of contact partly defines the friction forces that move the workpiece through the roll bite [11], being a fundamental aspect of the process. Accurate prediction and control of friction in these processes are highly desirable, since they contribute to an optimised process in terms of energy consumption
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
