Homogenisation of elastic properties in FDM components using microscale RVE numerical analysis

Abstract

Fused deposition modelling (FDM) is an additive manufacturing method having the potential to fabricate functional components. As the inherent nature of additive structures, the component stiffness depends on the build parameters such as layer height and raster orientation in addition to the filament material properties. Even on FDM prints with 100% infill density, voids are formed along the interface of rasters and contribute to the characteristics of the component. The primary role of the present work is to determine elastic characteristics such as Young's modulus, shear modulus and Poisson's ratio of FDM components and study the effect of build parameters. The void geometry identified from the cross-sectional morphology was used to create a microscale representative volume element (RVE) model capturing the characteristics of the FDM print. The elastic constants of the microscale model RVE were estimated by volume average method and homogenised over the entire structure. The study also investigated the influence of layer height on the elastic behaviour of FDM components in two different raster orientations of 0° and 0°/90°. Both the conditions exhibited directional characteristics and the elasticity constants approaches filament characteristics with decreases in the layer height. The modulus of elasticity was found maximum in the direction of raster orientation, whereas the elasticity modulus along vertical direction exhibited the lowest. The components with 0°-90° raster orientation exhibited transversely isotropic characteristics. Thus, the actual cross-sectional morphology-based microscale numerical analysis can effectively predict the directional attributes of FDM prints.

The effect of process parameters on the mechanical properties of additively manufactured parts using a hierarchical multiscale model

“…The rasters are oriented at different angles for 0–90, 90–0 and 45–45 degree orientation unlike in 0 degree; hence, the poor bonding and voids cause the printed part poor mechanical strength. The value for 100% infill for the 0.1 mm height sample, the experimental as well as computational results agree with the results presented in the literature (Anoop and Senthil, 2019). The quantitative error estimation is tabulated in Table 3.…”

Bead geometry–induced stress concentration factors in material extrusion polymer additive manufacturing

“…The objective of our study is to isolate and quantify the stress concentrations associated with the bead shapes, for applications where post-processing operations are not desirable or are infeasible. In addition to affecting the strength of the material, the bead shapes also contribute to the variability in the material properties, as observed in many studies empirically (Ahn et al , 2002; Özen et al , 2021; Papon and Haque, 2020; Popescu et al , 2018) and also through numerical modeling (Alaimo et al , 2017; Anoop and Senthil, 2019; Garzon-Hernandez et al , 2020; Rodríguez et al , 2003; Xia et al , 2018). This is because stress concentration is dependent on bead geometry, which in turn is dependent on processing parameters (Comminal et al , 2018; Di Angelo et al , 2017; Serdeczny et al , 2019, 2018; Spinnie and Smith, 2016).…”

Experimental Investigation on the 3D Printing of Nylon Reinforced by Carbon Fiber through Fused Filament Fabrication Process, Effects of Extruder Temperature, and Printing Speed

“…Considering the literature [13], the significant topic in the field of FDM is examining manufacturing parameters' impact on mechanical characteristics and optimization techniques to obtain the best properties. Appropriate researches have been performed in other fields like numerical analysis [14,15]. The significant effect of printing parameters on the properties of the final manufactured component and the use of novel geometric parameters.…”