Static response of synclastic sandwich panel with auxetic wood-based honeycomb cores subject to compression

Only a few research works show a method for creating doubly curved surfaces using single-layer auxetic structures. There are no studies regarding sandwich wood-based synclastic panels with the auxetic core. The main goal of this work was to determine the effect of the thin facings on the stiffness, strength, amount of absorbed energy, and damage of the synclastic panels with an auxetic core subjected to static compression. The facings of sandwich panels were manufactured out of cardboard and a copolyester of polyethylene terephthalate glycol (PETG). WoodEpox® composite was used as a material of the core structure. Synclastic panels were tested experimentally and analyzed using the finite element method. In addition, the damage process of the core and facings was described. The results of studies have shown a significant impact of the facing type of sandwich panel on its overall stiffness and ability to absorb energy. Cardboard panels are significantly more rigid than those made of PETG. Also, cardboard panels show a high ability to absorb energy. • Wood-based synclastic sandwich panels with an auxetic core were manufactured. • The effect of facings was analyzed. • The strength, stiffness, energy absorption, and damage were analyzed. • The numerical calculations were adopted. • A positive correlation between the type of facings and the mechanical properties was confirmed.