Enhancement of Anisotropic Strength of Fused Deposited ABS Parts by Genetic Algorithm

Fused Deposited Modeling (FDM) is one of the Rapid Prototyping (RP) processes that use thermoplastics to fabricate parts layer by layer. The parts built using ABS M30 plastics using FDM shows anisotropic property. This direction-dependent failure criterion results in parts with strength lesser than the maximum possible available strength. Also the orientation for building the parts is selected by the proprietary software based on minimum fabrication time and material consumption. When it comes to sand casting patterns, tensile strength and density play a major role in determining its service life and load bearing capacity. So in this paper an attempt has been made to study the dependency of process parameters (orientation, raster angle, raster width and air gap) on tensile strength and density. The design of the experiment is formulated based on Face Centered Central Composite Design (FCCCD). Response plots are plotted to study how the levels of process parameters influence each other in the resulting response. Scanning Electron Microscope (SEM) images are taken to study the fracture surface of the specimen. The multi-objective optimization of tensile strength and density is performed by using Non-Dominated Sorting Genetic Algorithm (NSGA-2).