Investigating Effects of Fiber Layers in 3D Printed Carbon Fiber Reinforced Polymer Composites

Abstract

The prominence of carbon fiber reinforced polymers (CFRP) has made advancements in many industries including aerospace, automotive, and sporting goods. Using additive manufacturing to produce the CFRPs allows prototyping complex geometries while keeping the structure lightweight and producing a high strength material. This work studies the printing parameters and flexural strength of 3D printed onyx based CFRP samples, looking at the effect of variable parameters affecting the carbon fiber layers. A Markforged Mark 2 3D printer, which utilizes a dual head print head, is used to print nine different configurations of the CFRP composite. Each sample consists of 24 layers of material with an infill of 50%, two wall layers, as well as four roof and floor layers. The configurations examine the extreme of three parameters with reference to the carbon fiber, being the fiber angle, number of fiber layers, and the position of the fiber layers. The carbon fiber print angle is printed with layers at 0Ëš, 0Ëš/45Ëš, and 0Ëš/90Ëš with the latter two switching between the respective angles for every layer of carbon fiber printed. The number of fiber layers are set to be either 4 or 16. The position of fiber layers includes all layers (excluding roof/floor); the two outer most layers (which are directly below/above the roof/floor layers); and the four middle layers of the sample. The 3D printed CFRP specimens are subjected to three-point bend test, and three samples are tested for each configuration. One sample is chosen from each configuration to undergo pre-test and post-test inspection using X-ray micro-computed tomography to examine any internal damages.