Cyclic compression behavior, energy absorption and dissipation efficiency of TPU-based BCC and FCC lattice structures: An experimental and statistical modeling study

Thermoplastic polyurethane (TPU) lattice structures manufactured using fused filament fabrication (FFF) are promising for lightweight and energy-absorbing applications. The current work investigates the cyclic compressive response of body-centered cubic (BCC) and face-centered cubic (FCC) TPU lattices through varying cell size, strut diameter, maximum compressive strain, and number of loading–unloading cycles. Specific quasi-elastic modulus, specific compressive stress at 20% strain, specific energy absorption, and energy dissipation efficiency were quantified. Four multivariable statistical models were elaborated to predict these responses and revealed high predictive accuracy in validation. Gibson-Ashby power-law relationships served to compare BCC and FCC architectures at equivalent relative densities. At a maximum compressive strain of 30% and four loading-unloading cycles, FCC displayed higher values for all investigated responses. As relative density rose from 0.1 to 0.7, FCC improvements dropped from 122% to 18% for specific quasi-elastic modulus, 74% to 34% for specific compressive stress, 50% to 36% for specific energy absorption, and 17% to approximately 8% for energy dissipation efficiency. These findings quantify the architecture-dependent cyclic performance of TPU lattices and provide predictive relationships for the investigated responses.