Congratulations Rojin! Her paper “Extended finite element method (XFEM) modeling of fracture in additively manufactured polymers” was accepted for publication in the journal of Additive Manufacturing. Here is the abstract (the paper link):

Extended finite element method (XFEM) modeling of fracture in additively manufactured polymers

R. Ghandriz¹, K. Hart², J. Li^1*

¹Department of Mechanical Engineering, University of Massachusetts, Dartmouth, MA 02747

² Milwaukee School of Engineering, Milwaukee, WI 53202

The fracture of additively manufactured polymer materials with various layer orientations is studied using the extended finite element method (XFEM) in an anisotropic cohesive zone model (CZM). The single edge notched bending (SENB) specimens made of acrylonitrile-butadiene-styrene (ABS) materials through fused filament fabrications with various crack tip/layer orientations are considered. The XFEM coupled with anisotropic CZM is employed to model the brittle fracture (fracture between layers), ductile fracture (fracture through layers), as well as kinked fracture behaviors of ABS specimens printed with vertical, horizontal, and oblique layer orientations, respectively. Both elastic and elastoplastic fracture models, coupled with linear or exponential traction-separation laws, are developed for the inter-layer and cross-layer fracture, respectively. For mixed inter-/cross- layer fracture, an anisotropic cohesive zone model is developed to predict the kinked crack propagations. Two crack initiation and evolution criteria are defined to include both crack propagation between layers (weak plane failure) and crack penetration through layers (maximum principal stress failure) that jointly determine the zig-zag crack growth paths. The anisotropic cohesive zone model with XFEM developed in this study is able to capture different fracture behaviors of additively manufactured ABS samples with different layer orientations.