Structure-property relationship of fused filament fabricated PEEK-based triply periodic minimal surface (TPMS) lattice structures: Experimental and computational design space analysis

Triply periodic minimal surface (TPMS) structures, known for their high-strength and porosity, show promise for various engineering applications. However, the interplay between their mechanical properties and morphological features remains poorly understood. This study investigates structure-property relationships in TPMS lattice structures fabricated using fused filament fabrication with PEEK material. This is the first study to apply a design space methodology to TPMS lattices, particularly gyroid and diamond, offering new insights into the relationship between cell size, thickness, pore size, and porosity under application and manufacturing constraints. Mechanical response maps under compression loading were obtained computationally and experimentally. The effective modulus of gyroid ranged 128.23 ± 0.75 to 70.66 ± 4.65 MPa, while for diamond, it ranged from 108.58 ± 7.05 to 66.23 ± 7.22 MPa, experimentally. Yield strength values for gyroid ranged from 16.84 ± 1.76 to 3.56 ± 1.52 MPa, while diamond ranged from 6.83 ± 0.76 to 3.92 ± 0.07 MPa, experimentally. Our computational results exhibited trends similar to the experimental data in terms of failure modes, although some discrepancies were observed. These discrepancies appear to be linked to manufacturing errors, which are more pronounced for PEEK due to its difficulty in FFF printing, especially when dealing with complex geometries like TPMS. This work provides critical insights into manufacturable TPMS solutions and their mechanical performance, advancing the design and optimization of TPMS structures for diverse applications. • Developed design maps for PEEK-based TPMS lattices via additive manufacturing. • Structure-property relationships for TPMS structures are investigated. • Morphological features visualized against requirements & constraints. • Established robust tools for optimizing TPMS designs for biomedical applications.