A finite element approach for modelling the fracture behaviour of unidirectional FFF-printed parts

TL;DR

This paper introduces a finite element modeling approach to simulate the fracture behavior of unidirectional FFF-printed parts under tensile stress, capturing failure modes and strength dependence on print orientation.

Contribution

It presents a novel finite element method tailored for FFF-printed specimens, accurately representing their mesostructure and failure mechanisms under tensile loading.

Findings

Successfully modeled failure modes for different print orientations

Demonstrated the dependence of strength on print orientation

Provided guidelines for representing characteristic edges in simulations

Abstract

We present a finite element modelling approach for unidirectional Fused Filament Fabrication (FFF)-printed specimens under tensile loading. In this study, the focus is on the fracture behaviour, the goal is to simulate the mechanical behaviour of specimens with different strand orientations until final failure of the specimens. In particular, the aim is to represent experimentally observed failure modes for different print orientations and the typical dependence of the parts strength on the print orientation. We investigate several modelling aspects like the choice of a suitable failure criterion, a suitable way to represent fracture in the finite element mesh or the necessary level of detail when modelling the characteristic edges of FFF-printed specimens. As a result, this work provides an approach to model FFF printed specimens in finite element simulations, which can represent the characteristic relation between mesostructural layout and macroscopic fracture behaviour.