constrained only in the direction perpendicular to the top surface of the beams. The intrinsic material properties for the regions which contained carbon fiber was set according to Equation [1]. The tensile test was not explicitly simulated since we have assumed that the strain between fiber and polymer matrix is ideally transferred. In that case it is possible to use equation (1) directly to calculate the theoretically predicted elastic properties of the printed specimens. RESULTS Effect of Fiber Layout in Flat Geometries In a first step, the effect of fiber volume fraction and fiber layout on the mechanical performance of flat samples was experimentally investigated. Therefore, thin rectangular beams were printed that consisted of a number of layers in which carbon fibers were integrated in the PETG matrix parallel to the length of the beam, as schematically shown in Figure 1. The fiber volume fraction was varied in two different ways: one in which different layers contained either fiber reinforced PETG or unfilled PETG (called the sandwich layout) and another in which all layers of the sample contained the same (varied) amount of fibers, on the sides Figure 4. Tensile modulus of flat samples with varying fiber volume fraction. of the layers (called the perimeter layout). Also, a reference PETG sample not containing any carbon fiber was included in the study. All geometries were subjected to two different load conditions: (a) tensile loading parallel to the length of the beam (and the fibers), (b) dynamic flexural loading perpendicular to the length of the beam (and the fibers). Experimental data were compared with the predictions of the theoretical and numerical models described above. Visit the online SAMPE store On-demand video presentations, conference proceedings and technical papers SAMPE members get unlimited free technical papers and discounted prices to all the products available in the online store. If you're not a member, sign up today at nasampe.org/ membership. CAMX 2021 Conference Proceedings Start Browsing Today nasampe.org/store NEW www. sampe.org NOVEMBER/DECEMBER 2021 | SAMPE JOURNAL | 59http://www.nasampe.org/ http://www.nasampe.org/store http://www.sampe.org