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•Thirty PC specimen made with FDM were tested contributing to data availability.•Correlation of physical test and Finite Element Analysis has been performed.•FEA isotropic model may ...be better than orthotropic model for elastic region.•Manufacturing parameters affect mechanical response besides building orientation.
Building end-use functional parts with additive manufacturing (AM) technologies is a challenging task. Several factors influence their surface finish, dimensional accuracy, mechanical properties and cost. Their orientation inside the building chamber is one of the most significant factors in AM processes. When using Fused Deposition Modeling (FDM) to build such parts, additional factors must be considered.
This paper aims to accomplish two purposes: finding a good model to simulate FDM parts and correlating a finite element analysis (FEA) simulation with physical testing.
The first objective was achieved by experimental tensile test of specimens to determine the nine mechanical constants that defines the stiffness matrix of an orthotropic material. Three Young’s modulus, three Poisson’s ratio and three shear modulus were experimentally obtained as well as yield tensile and ultimate strength of each specimen.
A simple part was designed and manufactured in different orientations to be physically tested and simulated to achieve the second objective. Polycarbonate (PC) was used as part material. Combined loading including bending and torsion was used. Differences on mechanical response were observed during the physical test of the parts depending on the building direction. Conclusions comment results and the convenience of using a different constitutive model depending on the design and use specifications.
This report presents an experimental investigation on the influence of part build orientation on the flexural fatigue behaviours of fused-deposition modelling (FDM) processed polycarbonate (PC) ...parts. Quantification of fatigue behaviour is required to show the feasibility of manufacturing industrial parts with the FDM technique. Therefore, stress-cyclic strain (S-N) curves were experimentally obtained for alternating stress (R − 1) and mean stress (R − 0.5). Test performances show that the part build orientation significantly affects the dynamic behaviour of FDM parts because of the inner anisotropy. Furthermore, to prove the validity of simulation methods such as finite element analysis (FEA), a case study was conducted. A designed part was simulated with FEA and the obtained von Mises stresses were corrected using the Goodman correction and the S-N curve for R − 1. This part was also manufactured and tested to compare the simulated and experimental results. The results show good accuracy between the virtual and physical models.
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•The flexural fatigue characteristics of PC parts manufactured by FDM are investigated for different stress ratios.•The part build orientation parameter significantly affects the dynamic behaviour; the XY and YZ are the most favourable.•A validation by FEA is addressed; a good correlation between the experimental and simulated data was achieved.
This paper presents an experimental investigation on the influence of process parameters such as part orientation, air gap and number of contours along with their interactions on the creep behaviour ...of fused deposition modelling (FDM) processed polycarbonate (PC) parts. Due to the lack of creep curve data with parts processed by FDM, this research gives a first quantitative approach to the time-dependent mechanical properties. This study not only varies significant process parameters viz., part build orientation, raster to raster air gap and number of contours, but also applies different loads to the samples to further understand primary and secondary creep behaviour for PC, providing the creep curves. Furthermore, two mathematical models are used to fit the experimental data, which can be used in numerical modelling. The first model is the well-documented and commonly used Bailey-Norton equation. As a second model, the fractional Voigt Maxwell in series (FVMS) is proposed to use. This model applies fractional calculus to reduce the number of parameters to be calculated. Conclusions obtained about how process parameters affect the creep behaviour are in agreement with previous research in mechanical properties of FDM parts.
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•The primary and secondary creep characteristics of polycarbonate parts manufactured by fused deposition modelling is investigated.•The influence of process parameters viz., part build orientation, air gap and number of contours on creep behaviour is discussed.•Novel creep curves up to four different stresses for 300 and 1000min were experimentally addressed.•The Bailey-Norton equation and the fractional Voigt-Maxwell in series models are used to fit the experimental data.
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