PSI - Issue 79

Alessandra Ceci et al. / Procedia Structural Integrity 79 (2026) 73–80

74

Keywords: Metal Cubic Lattice Structures; Triply periodic minimal surfaces (TPMS); Lost-PLA Casting; Aluminum alloy; Mechanical strength of Lattice Structures; Specific Absorbed Energy.

1. Introduction Cellular structures represent a promising frontier in the design of advanced materials, characterized by regular or irregular geometries that combine lightweight, mechanical strength and energy dissipation capabilities. These structures are often inspired by biological systems such as trabecular bone or honeycombs, which exhibit optimal load distribution and mechanical efficiency (Pehlivan et al., 2025). Growing interest in this area is driven by the exceptional mechanical performance of cellular architectures, especially when fabricated using additive manufacturing (AM) technologies that allow for unusual design freedom (Bari and Bollenbach, 2022). Complex geometries, such as Triply Periodic Minimal Surfaces (TPMS), have shown enhanced performance in energy absorption, stiffness-to-weight ratios and biomechanical adaptability (Pehlivan et al., 2025; Shahriyari et al., 2025). These architectures have found applications in technology-intensive sectors, including:  Automotive: Cellular structures are integrated into energy-absorbing components, such as crash boxes and bumpers, to enhance passive safety and reduce weight (Bieler and Weinberg, 2024a)  Aerospace: The demand for ultralight yet strong components is met by lattice-based architectures used in sandwich panels and structural frameworks (Bieler and Weinberg, 2024b).  Biomedical: Porous cellular designs mimic bone morphology and enhance osseointegration in orthopedic implants, especially when manufactured from bio-compatible alloys like Ti-6Al-4V (Farshbaf et al., 2025; Maskery et al., 2015, p. 6)  Manufacturing/Industrial sector: Cellular materials provide effective load distribution, high specific stiffness, and damage tolerance in lightweight support structures (Catar et al., 2024).  Energy: Their application in heat exchangers and thermal dissipative structures is expanding due to their high surface area and low density (Ceci et al., 2025b; Sadeghi et al., 2018; Sequino et al., 2023). Current challenges include multiscale modeling, topology optimization, and integration with multifunctional materials, but advancements in computational design and AM are rapidly accelerating their adoption (Ceci et al., 2025a; He et al., 2022). 2. Materials and Methods Parametric design enabled the definition of a unit cell inscribed in a 1 cm cube, with continuous geometry inspired by Triply Periodic Minimal Surfaces (TPMS), described by Equation (1). The geometric parameters a and b control wall thickness and connectivity, directly affecting relative density and stress distribution. The two configurations, Structure 1 (a=0.5, b=1.2) and Structure 2 (a=0.5, b=0.8), correspond to a more porous and a denser structure, respectively, as shown in Fig. 1a-c. � , , � � � 2 � � � 2 � � � 2 � �� ∙ � � 2 � ∙ � 2 �� � � 2 � ∙ � 2 � � � 2 � ∙ � 2 � � � � 0 (1) Repetition of the cell generated cylindrical specimens (Ø=46.5 mm × h=60 mm), Fig. 1 b-d, suitable for compression testing. The chosen dimensions balance the need for sufficiently large samples for reliable mechanical analysis with the limitations of the casting process. The manufacturing process involved several stages, summarized in Fig. 2 (only for Structure 1). PLA models were printed using an Ultimaker S3 (0.4 mm nozzle), with slicing parameters carefully optimized to ensure dimensional accuracy. Any imperfection in the polymer model is directly reproduced in the final metal part, making this stage crucial. Models were embedded in investment plaster and cured for 24 h to avoid cracking or evaporation defects. Burnout was performed in a muffle furnace up to 900 °C, ensuring complete PLA removal to prevent carbon residues and internal defects. The AA6082 alloy was gravity cast at 850 °C into pre-heated molds, minimizing thermal gradients and improving infiltration of the molten metal. Compared to