Investigating the fracture behavior of 3D printed orthotropic porous materials under mixed-mode I/II loading
Year: 2025
Type: article
Abstract: Porous materials possess holes, voids, and free space within their structures. Typically, these pores exhibit a random shape, size, and orientation distribution. The complexities in the structure affect the overall properties of these materials. This work investigates the fracture behavior of orthotropic porous materials using theoretical and experimental approaches. Two novel mixed-mode criteria are developed based on the overall mechanical properties of porous materials derived from uniform deterioration across directions (UDAD) and a combination of generalized elastic moduli with a reinforced isotropic solid model (GE-RIS) methodology. Several experimental tests were conducted on single-edge notch tensile (SENT) specimens of Polylactic Acid (PLA) reinforced with short fibers. The intricate nature of the geometries necessitated the use of the fused deposition modeling (FDM) technique for manufacturing. These specimens were designed to have a random distribution of pores in shape, size, location, and orientation, with porosity varying from 0 to 0.4. With the determination of the fracture load for each case, the critical stress intensity factors (SIF) were calculated using the finite element method. The results indicate that the stress intensity factor depends on porosity, and increasing porosity reduces the failure load but raises the critical SIF of these materials. Additionally, the effect of porosity on the material's fracture toughness is included in the developed mixed-mode I/II criteria. These criteria can serve as upper and lower bounds for estimating the fracture of porous materials. Finally, the proposed criteria were validated with experimental results.
Source: Polymer Testing
Institution: University of Tehran
Language: English
Subfield: Mechanics of Materials
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,370
OpenAlex ID: W4413804343
