Uniaxial crushing of sandwich plates with continuously density-graded cellular cores subjected to impulsive loading

The continuously density-graded cellular materials have great potential to mitigate the impact damage of structures under intensive loading. In this article, we theoretically and numerically investigate the uniaxial crushing of continuously density-graded cellular cores in sandwich plates subjected to impulsive loading. Four types of core density distribution are investigated: positive, negative, middle-high and middle-low. The theoretical predictions agree well with the 2D Voronoi finite element results. Based on the yield acceleration function, it is found that different shock modes may occur in the crushing core, depending strongly on the core density gradient. Discussions on maximizing the densification impulse and mitigating the back-face acceleration show that density-graded cellular materials may be helpful in optimization of the sandwich plates.