Authors: Chase Mortensen, Juhyeong Lee
Mentors: Juhyeong Lee
Insitution: Utah State University
Foldcore sandwich composites (FSCs) are constructed using multi-layered sheets folded in a desired pattern and placed between two thin face sheets. The choice of material geometric folding pattern provides a large design space to optimize the structural performance of FSCs. These composites are typically made of carbon fiber reinforced polymer (CFRP) composites, offering lightweight and high-energy-absorbing properties. This work aims to characterize the size effects of unit-cell foldcores by analyzing the influence of subscale foldcore models subjected to periodic boundary conditions under quasi-static compression. Three Miura-based unit-cell foldcore models were considered: (1) 1×1, (2) 1×2 (two 1×1 unit-cell foldcores connected in parallel), and (3) 2×1 (two 1×1 unit-cell foldcores connected perpendicularly). Through finite element modeling, three key findings were derived: 1) the finite element model closely replicated experimental results; 2) the application of periodic boundary conditions had an insignificant impact on subscale foldcore models. Third, inconsiderable variations in stress and damage were observed primarily along the foldcore creases when unit-cells were placed in parallel.