Distortion analysis in large-scale additive manufacturing using finite element method

The mechanical properties and deformations of materials produced in large-scale additive manufacturing with different mixing ratios were investigated on the produced samples in this thesis. In the parts produced by additive manufacturing, residual stresses occur on the part due to the transition from liquid to solid. Residual stresses cause unwanted deformation. Shape changes are more prominent in parts produced on a large scale, and this brings a significant limitation in production. In order to overcome these limitations, samples were produced using the homogenization technique of fiber orientations in 15%, 10%, 5%, and 0% carbon fiber-reinforced Acrylonitrile Butadiene Styrene (ABS) by weight. Experimentally, the amount of distortion of the parts modeled according to these carbon fiber ratios was examined, the cooling times were followed, and the results were compared by finite element analyses. In addition, the flexural bending strengths of the samples were investigated by bending tests in accordance with the ASTM D790 standard. The finite element analysis results show 10-20% higher distortion than experimental ones. The maximum flexural strength was obtained for a 5% carbon fiber reinforced specimen among all specimens. The porosity formation for the specimens having more amounts of carbon fibers (10%-15%) reduced the flexural strength According to the results from FEA, pure ABS has the highest distortion whereas 10% ABS-CF has the least distortion.