An experimental investigation of impact behaviour of continuous fiber reinforced composites produced by fused deposition modelling (FDM) method

Additive manufacturing which has been developed in the recent half century is promising manufacturing technology. It uses layer-wise manufacturing method to obtaining end product. In last years, thousand researches have been made but there are still vacancies about mechanical properties, especially impact studies. In this study, first, the effect of layer thicknesses, infill rate, infill pattern and impact speed were investigated on the fracture mechanics of 3D printed samples via drop weight impact test. The specimens were produced using Fused Deposition Modeling (FDM) Method with various infill patterns, infill rates and different layer thicknesses. PLA and ABS materials were used for the samples which investigation of production parameters. 0.2, 0.15, 0.1 mm layer thickness were examined. Linear, Cubic, Triangle, Concentric, Cubic Subdivision and Tetrahedral infill types are used. For Cubic Subdivision infill type, 20%, 40%, 60% and 80% infill rates and for linear infill type, 20%, 40%, 60%, 80% and 100% infill rates were chosen for examining the effect of infill rate. As a result of the tests, it is observed that the layer thickness doesn't not affect the fracture behavior. It has been observed that different infill types affect the amount of energy absorbed and the fracture behavior in different ways. As the infill rate increases, it is found to give toughness to the part. After this study, continuous fiber reinforced 3D samples were produced by combining FDM with vacuum infusion method. Glass fiber and carbon fiber were used as reinforcement material, ABS was used as matrix material and epoxy resin was used as binder. Tensile and impact test specimens were produced with the novel production method and tested. The results obtained were compared with the pure ABS sample. The findings show that glass fiber increases impact strength but decreases tensile strength. It has been observed that carbon fiber reinforcement does not change the impact strength and decrease the tensile strength. This is because inter-layer and layerto-fiber adhesion is not sufficiently achieved. For this reason, the load is not distributed in a balanced form. However, both reinforcing materials affected the fracture mechanics of the sample and caused less fracture.