Monotonic and Cyclic Tensile Properties of ABS Components Fabricated by Additive Manufacturing

An investigation of tensile strength and cyclic tension-tension fatigue behavior has been performed on layered ABS components fabricated by fused deposition modeling (FDM). Experimentation was designed to focus specifically on the effect of specimen mesostructure on monotonic tensile behavior and tensile-fatigue life. Analyzed mesostructures include unidirectional laminae with parallel fiber orientations ranging from θ = 0° (aligned with the loading axis) to θ = 90° (perpendicular to the loading axis), and alternating laminae with a layering pattern of θ°/(θ-90°) fiber orientations. The unidirectional 0° specimens achieved the greatest tensile strength and effective elastic modulus, while the alternating +45°/-45° specimens displayed the best fatigue performance of the specimens tested. Results highlight the anisotropic behavior of FDM components and suggest that the tensile behavior is improved by aligning the fibers of unidirectional laminae more closely with the axis of the applied stress. In addition, the specimens with θ°/(θ-90°) fiber orientations displayed incrementally improved tensile properties and fatigue performance from an apparent offsetting effect that results from alternating laminae. The fracture surfaces of the specimens were analyzed using scanning electron microscopy in order to gain further insights into the fatigue damage and failure mechanisms.