Impact properties of an end of life tires' rubber. Numerical validation considering large strain and strain rate conditions

Abstract

In a previous work, the experimental viscoelastic properties of a renewed rubber obtained from the recycling of end-of-life tires (ELTs) were presented, [1]. The material was tested in the laboratory by means of impact tests that revealed how the behavior of the rubber depends on the strain rate in such a case. Due to the loading conditions of high strains and high strain rates, the nonlinear viscoelastic Bergtröm-Boyce (BB) model, defined by nine parameters, was selected to fit the behavior of the material.

To obtain the parameters from the results of the impact tests, different optimization methods were used. As many sets of nine parameters were obtained as optimization methods were considered, with notable differences between them in some cases.

The motivation of this work is to know which set of parameters, i.e. which optimization method, is the most appropriate. With this objective, a complete comparative numerical analysis of these sets, forty-eight in total, has been developed by means of simulations performed in LS-DYNA software.

As a result of this analysis, the model that best suits the behavior of the material for the load case studied was chosen. This work completes the first step to reach the final objective of our research, which is to numerically analyze the behavior of systems designed to absorb energy in impact events based on this material.

[1] DOI: 10.1016/j.polymertesting.2021.107468