Enhancing the Dimensional Accuracy of Components Fabricated Using Rapid Prototyping Technique by Optimizing Machine Parameters of a 3D Printer This research was focused on enhancing the dimensional accuracy of 3D printed products while studying the effect of 3D printer parameters on the geometry of 3D printed components by conducting a Fractional Factorial DoE. The efficiency of 3D printers is increasing when the layer thicknesses are increasing. MakerBotxc2xae have three layer thicknesses (0.1 mm, 0.2 mm and 0.3 mm) and printing efficiency is high when the layer thickness is high (0.3 mm), but the quality, i.e. the dimensional accuracy of the printed product is very low compared with the products printed with small layer thicknesses. This study comprises five MakerBotxc2xae 3D printer parameters (extruder temperature, speed while extruding, fan power, number of shells and infill pattern) in order to identify their optimum settings to improve the dimensional accuracy of a 3D printed product with high layer thickness (0.3 mm). The analysis results show that it is difficult to identify common optimum factor settings to enhance the dimensional accuracy of every component of 3D printed product, but it was possible to identify the common factor settings for similar geometries such as spherical shapes, cubic shapes, etc.

Material characterization and precise finite element analysis of fiber reinforced thermoplastic composites for 4D printing Abstract   Fourdimensional (4D) printing, a new technology emerged from additive manufacturing (3D printing), is widely known for its capability of programming postfabrication shapechanging into artifacts. Fused deposition modeling (FDM)based 4D printing, in particular, uses thermoplastics to produce artifacts and requires computational analysis to assist the design processes of complex geometries. However, these artifacts are weak against structural loads, and the design quality can be limited by less accurate material models and numerical simulations. To address these issues, this paper propounds a composite structure design made of two materials  polylactic acid (PLA) and carbon fiber reinforced PLA (CFPLA)  to increase the structural strength of 4D printed artifacts and a workflow composed of several physical experiments and series of dynamic mechanical analysis (DMA) to characterize materials. We apply this workflow to 3D printed samples fabricated with different printed parameters to accurately characterize the materials and implement a sequential finite element analysis (FEA) to achieve accurate simulations. The accuracy of deformation induced by the triggering process is both computationally and experimentally verified with several creative design examples and is measured to be at least 95%, with a confidence interval of     (  0  .  972  ,  0  .  985  )    . We believe the presented workflow is essential to the combination of geometry, material mechanism and design, and has various potential applications.