THE INFLUENCE OF GRADIENT PROFILE ON THE DYNAMIC PROPERTIES OF DENSITY GRADED METAL HOLLOW SPHERE ARRAYS

The determinations of gradient and gradient profile are the key point in the design of density graded metal hollow sphere arrays. In this paper, the influence of the gradient profile on the dynamic responses of density graded metal hollow sphere arrays is investigated. The results show that under a low velocity impact, the dynamic responses of density graded metal hollow sphere arrays only depend on the gradient. Whilst under a medium or high velocity impact, the dynamic properties rely not only on the gradient, but also on the gradient profile. Under certain impact velocity, the gradient profile determines the stress distribution, but the energy absorption relies on the relative density of the materials. Considering the protection to structures, the gradient profiles with the high density layer near the impact end and the low density layer near the distal end are recommended. The results will provide valuable suggestions in the multi-objective optimization design of impact dynamic properties of porous materials.