Plastic deformation of similar and dissimilar multi-layered metallic plates with the same areal density subjected to repeated impulsive loading

In the current research study, the large plastic deformations of similar and dissimilar single- and multi-layered metallic plates with the same areal density under repeated uniform impulsive loading have been investigated. The ballistic pendulum along a 200 mm length standoff blast tube was used to apply the blast load on the specimen. Forty testing specimen in three different layering configurations including single-, double, and triple-layered, and eight different arrangements were considered. For the same loading and experimental condition, 10 g plastic explosive was utilized and the dynamic response of structures was studied up to five consecutive loads. The experimental results indicated large plastic global deformation with thinning happening at the clamped boundary and also tearing for some experiments. The results also represented that the maximum permanent deflections of plates were increased by the number of blast loads and the progressive deflection of the plates at the center was decreased exponentially with increasing the number of blasts. Placing a thick front layer a thin back layer gives better blast performance to the tested specimen against repeated impulsive loading. The obtained result for multi-layered configurations with the same material is completely consistent with those structures made of dissimilar layers.