Atomistic Modeling of the Effect of Temperature on Interfacial Properties of 3D-Printed Continuous Carbon Fiber-Reinforced Polyamide 6 Composite: From Processing to Loading.

The combination of continuous fiber-reinforced thermoplastic composites (CFRTPCs) and the continuous fiber 3D printing (CF3DP) technique enables the rapid production of complex structural composites. In these 3D-printed composites, stress transfer primarily relies on the fiber-resin interface, making it a critical performance factor. The interfacial properties are significantly influenced by the temperatures applied during the loading and forming processes. While the effect of the loading temperature has been extensively researched, that of the forming temperature remains largely unexplored, especially from an atomistic perspective. Our research aims to employ molecular dynamics simulations to elucidate the effect of temperature on the interfacial properties of continuous carbon fiber-reinforced polyamide 6 (C/PA6) composites fabricated using the CF3DP technique, considering both loading and forming aspects. Through molecular dynamics simulations, we uncovered a positive correlation between the interfacial strength and forming temperature. Moreover, an increased forming temperature induced a notable shift in the failure mode of C/PA6 under uniaxial tensile loading. Furthermore, it was observed that increasing loading temperatures led to the deterioration of the mechanical properties of PA6, resulting in a gradual transition of the primary failure mode from adhesive failure to cohesive failure. This shift in the failure mode is closely associated with the glass transition of PA6.

How Do Reference Points Influence the Representation of the N200 for Consumer Preference?

Recent studies have suggested that event-related brain potential (ERP) can represent consumer preference, and there is consensus that the N200 is the best indicator of consumer preference. Measurement of reference-dependent consumer preference, in turn, requires a reference point, but it remains largely unknown how reference points modulate the preference-related N200. We designed an experiment to investigate how reference points affect the N200 based on classical paradigms. In the single-reference condition, one product was displayed in each trial; in the conjoined-reference condition, a pair of products was displayed simultaneously. Our results showed that in the single-reference condition, low-preference products elicited more negative N200 than high-preference products, replicating previous results, but the N200 could not distinguish between low- and high-preference products when viewing two options of similar subjective value in the conjoined-reference condition. These findings suggest that reference points modulate the representation of the N200 on consumer preference. When only viewing one product, participants make a value judgment based on their expectations. However, when viewing two products simultaneously, both their expectation and the alternative product can serve as reference points, and whether the N200 can represent consumer preference depends on which reference point is dominant. In future research, reference points must be controlled when the N200 is used to explore value-related decision-making.