Notch Sensitivity Study in U-notched Polymers Built by Additive Manufacturing (AM)

Abstract

Onyx ® is a new material composed of Polyamide 6 reinforced with short carbon fiber, used in the novel additive manufacturing composites technique. This paper aims to present the axial fatigue performance of this material with and without U-notches. The experimentally determined S-N fatigue curve was obtained under axial load with a load inversion ratio, R = 0.1, and compared to fatigue performance of U-notched samples ranging from 0.25 to 2 mm radius. In addition, the stress concentration factor was compared for static and alternative loading to obtain the notch sensitivity in terms of the U-notch radius, showing that there is indeed a difference in stress concentration between them. The advantage of the approach is that it permits using commonly used dimensioning methods for this AM material.

Mechanical and Tribological Performance of Carbon Fiber-Reinforced PETG for FFF Applications

“…This effect might contribute to the alteration of the matrix's behavior and, consequently, result in a reduced elongation capacity due to the accumulation of reinforcements in critical zones of the specimen. Under this consideration, similar studies about mechanical properties show comparative results according to the main trends obtained in this research [34][35][36]. Regarding the tests with PETG-CF, as shown in Figure 11, a significantly different behavior is observed, showing a tendency of the material to reduce its performance as the layer thickness increases.…”