Issue 76

T. Hachimi et alii, Fracture and Structural Integrity, 76 (2026) 31-48; DOI: 10.3221/IGF-ESIS.76.03

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Figure 9: Influence of printing parameters and their interactions on virtual width (mm).

Although the two types of raster widths are not parallel to each other as shown in the interaction plot presented in Fig. 9, there are still various levels of interaction occurring between the printing parameters caused by this variation. The greatest impact of this interaction will be the variation in the structural integrity of the extruded filament; Components printed at a high speed and with wider raster widths will be able to create a stronger interlayer bonding strength, but will also be at risk of creating printable items with dimensional inaccuracy because they will have wider filaments. Components printed with narrower filaments will have lower viscosity due to higher temperatures, giving the material longer times to flow before it cools and settles and, therefore, will create filaments that are wider than would be expected. This confirms the need for a calibrated mathematical model to accurately predict filament geometry, which is essential for enhancing the fidelity of finite element simulations in Abaqus. Formula (1) provides an approximate calculation of the virtual width of the raster section used in generation.

2.23 3.9 5.6E-01 1.43E-02 6.8E-03 1.29E-01 ² 1.196 ² 2.2E-05 ² 6E-06 ² 2.5E-01 1.675E-02 1.13E-03 2.50E-03 9.5E-03 1.1E-06 w t w t s t w t s t w t t t s w t w s t s V L R E P L R E P L R L E L P R E R P E P                     

(1)

with

 V w : Virtual width (mm);  L t : Layer thickness (mm ;  R w : Raster width (mm);  E t : Extruder temprature (°C);  P s : Printing speed (mm/s).

In order to create realistic FDM computational sliding tests (modeling) using the software package 'Abaqus,' the first major step was the geometric integration of the empirically corrected filament cross-sections into the G-code toolpath derived from slicing software. In most cases, the simulation of the deposition process will use a circular or rectangular cross-section for printing, yet this does not realistically represent the actual deposition characteristics of FDM extrudates as they

experience various forms of deformation due to the following: - Compression of the filament due to the size of the nozzle. - The thermal expansion and contraction of the filament material. - The viscosity behaviour of the materials used for FDM printing. - The adhesion characteristics of the substrate to which the extrudate is being placed.

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