The Indentation Rolling Resistance in Belt Conveyors: A Model for the Viscoelastic Friction

Nicola Menga,Francesco Bottiglione,Giuseppe Carbone

doi:10.3390/lubricants7070058

Nicola Menga, Francesco Bottiglione + Show 1 more

Open Access

https://doi.org/10.3390/lubricants7070058

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Abstract

In this paper, we study the steady-state rolling contact of a linear viscoelastic layer of finite thickness and a rigid indenter made of a periodic array of equally spaced rigid cylinders. The viscoelastic contact model is derived by means of Green’s function approach, which allows solving the contact problem with the sliding velocity as a control parameter. The contact problem is solved by means of an accurate numerical procedure developed for general two-dimensional contact geometries. The effect of geometrical quantities (layer thickness, cylinders radii, and cylinders spacing), material properties (viscoelastic moduli, relaxation time) and operative conditions (load, velocity) are all investigated. Physical quantities typical of contact problems (contact areas, deformed profiles, etc.) are calculated and discussed. Special emphasis is dedicated to the viscoelastic friction force coefficient and to the energy dissipated per unit time. The discussion is focused on the role played by the deformation localized at the contact spots and the one in the bulk of the thin layer, due to layer bending. The model is proposed as an accurate solution for engineering applications such as belt conveyors, in which the energy dissipated on the rolling contact of idle rollers can, in some cases, be by far the most important contribution to their energy consumption.

Highlights

Polymers and rubber-like materials have found increasing utilization in mechanical devices and machines, because of some of their very relevant physical properties
For example, rubber materials are used to protect the core of the belt, preventing damages coming from aggressive environments and mechanical interactions, such as the rolling contact with the load-carrying idle rollers, as well as the abrasion induced by the conveyed material
A viscoelastic friction arises, which is often known as indentation rolling resistance [5]

Summary

Introduction

Polymers and rubber-like materials have found increasing utilization in mechanical devices and machines, because of some of their very relevant physical properties. In [41], the authors exploited the results of the confined viscoelastic layer achieved in [40] to investigate the viscoelastic contact between rigid, spaced cylinders and a thin layer of rubber material constrained to a rigid substrate They have characterized the viscoelastic friction arising in a moving contact, with the purpose of determining the damping behavior of a roller bearing viscoelastic isolator for seismic applications. The study allows determining the tangential viscoelastic frictional force (indentation rolling resistance) arising at the contact interface, as well as the energy dissipation per unit time, as functions of the system geometry, the mechanical properties of the viscoelastic layer and the operative conditions such as the layer velocity and the remote applied pressure

Physical Model

Results and Discussion

Conclusions