Strain Energy Dissipation Mechanisms in Carbon Nanotube Composites Fabricated by Additive Manufacturing

Abstract

Carbon nanotube (CNT) reinforced acrylonitrile-butadiene-styrene (ABS) composites fabricated using a fused deposition modeling approach were characterized for mechanical strain energy storage and dissipation capabilities. Dynamic mechanical analysis (DMA) was performed to quantify loss factor as a function of applied dynamic strain. In addition, DMA was performed at varying temperatures to give insight into the molecular interactions present in these composites. Insight into the microstructure was provided by atomic force microscopy (AFM). The results are compared to neat ABS and ABS/CNT systems processed through an injection molding technique. Results show large energy dissipation, accompanied by permanent damage, in both injection molded and additively manufactured neat ABS samples. In contrast, the additively manufactured ABS/CNT nanocomposites exhibited strain energy dissipation but reduced the effect of cavitation and crazing by possible reinforcement. This result suggests CNT fillers have the potential to alter the dissipation mechanisms present in additively manufactured structures to control structural damping. This research provides insight into the design and additive manufacturing of materials where energy dissipation is essential to maintain structural stability and functionality under dynamic loading.