Using numerical-experimental analysis to evaluate rPET mechanical behavior under compressive stresses and FFF additive manufacturing for new sustainable designs

TL;DR

This study combines numerical and experimental methods to analyze the compressive mechanical behavior of recycled PET (rPET) manufactured via FFF, validating its use for sustainable design applications and confirming its isotropic properties in simulations.

Contribution

It introduces a validated numerical-experimental framework for modeling rPET's compressive behavior, facilitating its use in sustainable additive manufacturing designs.

Findings

rPET behaves linearly until elastic limit in compression

Numerical and experimental results differ by only 0.001-0.024 mm

rPET can be modeled as isotropic in simulations

Abstract

The purpose of this study is to investigate the numerical-experimental mechanical behavior modeling of the recycled polymer, that is, recyclable polyethylene terephthalate (rPET), manufactured by a deposition FFF process under compressive stresses for new sustainable designs. In all, 42 test specimens were manufactured and analyzed according to the ASTM D695-15 standards. Eight numerical analyzes were performed on a real design manufactured with rPET using Young's compression modulus from the experimental tests. Finally, eight additional experimental tests under uniaxial compression loads were performed on the real sustainable design for validating its mechanical behavior versus computational numerical tests. As a result of the experimental tests, rPET behaves linearly until it reaches the elastic limit, along each manufacturing axis. The results of this study confirmed the design's structural safety by the load scenario and operating boundary conditions. Experimental and numerical results show a difference of 0.001-0.024 mm, allowing for the rPET to be configured as isotropic in numerical simulation software without having to modify its material modeling equations. The results obtained are of great help to industry, designers and researchers because they validate the use of recycled rPET for the ecological production of real-sustainable products using MEX technology under compressive stress and its configuration for numerical simulations. Major design companies are now using recycled plastic materials in their high-end designs. Validation results have been presented on test specimens and real items, comparing experimental material configuration values with numerical results.