PSI - Issue 80

R. Salem et al. / Procedia Structural Integrity 80 (2026) 256–268 Rania Salem / Structural Integrity Procedia 00 (2025) 000 – 000

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Rather than simulating the fabrication process itself, this study focuses on quantifying the mechanical consequences of porosity and imperfect interfacial bonding, particularly regarding the elastic response under tensile loading. The mesostructural features captured from tomography (Paux et al., 2023) or geometric analysis (Sahoo et al., 2024; Sola et al., 2023) are incorporated into RVEs, allowing the framework to resolve local stress concentrations induced by internal voids and inter-raster imperfections. These insights are essential for accurate homogenization and upscaling to predict macroscopic behavior.

(a)

(b)

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Fig. 1: Illustration of the presence of voids in an ABS lattice strut of section dimensions 1x4mm 2 printed with 3 adjacent and parallel filaments in each layer. The images were obtained from X-Ray micro-tomography. In (a), a 2D view on a section of the strut. In (b) the 3D reconstruction illustrating the prolongation of voids in the form of tunnels (in purple) along the filament deposition direction

2.1. Finite element modeling of elastic properties at the microscale 2.1.1 Microstructural RVE

At the microscale, finite element simulations are performed in ABAQUS standard using RVEs to model the heterogeneous microstructure of struts produced by FFF. These struts are composed of parallel filaments deposited in a square pile-up pattern ( Fig. 2a ), and our analysis is restricted to the tensile properties in the direction of filament deposition. The modeled microstructure includes four distinct phases as illustrated in Fig. 2 : (i) the bulk phase, which corresponds to the part of a filament not intersecting any neighboring filament, (ii) the phase of the void, (iii) the phase of the “horizontal bonding region’’, corresponding to the intersection between two vertically superimposed filaments, and (iv) the phase of the “vertical bonding region’’, corresponding to the intersection between two adjacent filaments in a same layer.

Fig.2: A representation of the deposition of the filament(a) and the geometric scheme of the RVE(b)