Mechanical strength of 3D printed objects: experimental and numerical investigation

Başara, Gözde
The number of people and the industries that are using 3 Dimensional (3D) printing increases everyday; however, the home-use of 3D printing remains below expectations partially due to limitation in the printer size. Many different technolo-gies can be used in 3D printing. In this study Fused Deposition Modelling (FDM) is used. This method is commonly used for home-use 3D printing. In FDM, there is a wide range of materials that can be used and for this study the material is chosen as Poly Lactic Acid (PLA) being one of the most commonly used materials. In this study, to understand the mechanical behavior of the used material, compression and tensile tests are performed and they are verified numerically. The compression tests are done for two infill percentages of the parts and the results are compared. 100% infill parts show better mechanical properties than parts having 20% infill. Tensile tests are done by using a whole specimen and two half specimens which are joined in the middle by using an adhesive. As a result, the difference in performance is ob-served. Glued specimens show lower performance. Afterwards, by using the results of the experiments numerical analyses are done. For the numerical analyses, ANSYS is used. The numerical results show consistency with the experimental results. Lastly, a case study is performed. In this case study, the effect of partitioning and joining the parts by using an adhesive, on the strength of the object is investigated for a mo-torcycle helmet. PLA was chosen as the material of the helmet and experimental results of PLA are used as the mechanical properties of the helmet. The results of whole helmet and partitioned helmet show similarity with a small difference under the same loading conditions. The stress results and the distribution of the stresses within the two helmets are also close to each other.