Synergistic Effects of Process-Driven Thermo-Physical Characteristics on Fracture Toughness and Fatigue Behaviors of Additively Manufactured Polymers
Abstract
The thermo-physical characteristics of polymeric materials produced using fusion-based material extrusion (MEX) additive manufacturing (AM) are sensitive to variations in process parameters. These parameters affect the as-manufactured defects (void content), which are known to impact the fracture and fatigue performance. However, the synergistic effects of process-driven thermo-physical characteristics and void content on fracture toughness and fatigue crack growth in MEX polymers remains inconclusive. In this work, polylactic acid (PLA) was manufactured with varying raster orientations (0° and 90°) and infill densities (80%, 85%, 90%, 95%, and 100%, as a proxy for void content). A series of experiments evaluated how these parameters influence void content, and therefore temperature distribution and resultant fracture and fatigue properties. Fracture toughness and fatigue crack growth were evaluated using compact tension specimens (CTS) and digital image correlation (DIC) to assess crack tip plasticity. The results indicate MEX samples printed with an orientation of 90° from the intended crack propagation exhibited a degradation in fracture toughness and fatigue performance. This degradation is primarily due to interlayer fracture caused by the voids being oriented perpendicular to the applied load, rather than the extent of the void content. These findings enhance the understanding of the interaction of process-driven thermo-physical properties and damage tolerance.
Recommended Citation
M. A. Jafor et al., "Synergistic Effects of Process-Driven Thermo-Physical Characteristics on Fracture Toughness and Fatigue Behaviors of Additively Manufactured Polymers," International Journal of Fatigue, vol. 201, article no. 109174, Elsevier, Dec 2025.
The definitive version is available at https://doi.org/10.1016/j.ijfatigue.2025.109174
Department(s)
Mechanical and Aerospace Engineering
Keywords and Phrases
Additive manufacturing; Fatigue; Fracture; Material extrusion; Semicrystalline polymer
International Standard Serial Number (ISSN)
0142-1123
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2025 Elsevier, All rights reserved.
Publication Date
01 Dec 2025
Comments
Baylor University, Grant None