Mechanical characterization of natural biodegradable sandwich materials

Natural biodegradable sandwich materials were fabricated and mechanical characterization was performed under flexural and impact loading conditions. The sandwich structure consists of hardwood as face plates, mushroom foam as a core, and natural glue as an adhesive. Two different hardwood layers were used to investigate the effect of thickness and the stiffness on the flexural and impact properties. Under impact loads, two different projectile velocities were employed to understand their effect on energy absorption of the sandwich materials. It was found that the sandwich made using high stiffness wood panels showed improved flexural properties as well as maximum energy absorption at higher impact velocities. The damage of front and rear sides of impact specimens was analyzed to understand the effect of impact velocity on damage zone. The damage area on the rear side of the specimen decreased significantly with high stiffness wood face plates at lower projectile velocity. The increase is energy absorption is better supported by the increase in damage area on both front and rear sides of sandwich materials at higher projectile velocity. Both flexural properties and energy absorption demonstrated great promise to use these sandwich structures for structural load bearing applications.