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Cellular metals with stochastic, 2D or 3D periodic microstructures can sustain large plastic deformation at almost constant stress. Due to such excellent energy absorption capability, cellular metals are very suited to be used as the core of sandwich structures, which have been applied widely to the areas of aerospace and aeronautical design, the automotive manufacturing, and shipbuilding, as well as the defense and nuclear industries. Although there is a great deal of research currently available related to the behaviour of sandwich structures with metallic cellular core under various loading conditions, they are widely scattered in the literature. This review paper brings together the latest developments in this important research area. Three types of cellular metals, namely metal foams, honeycombs and prismatic materials and truss and textile based lattice materials are considered. The responses of sandwich structure with such cores subjected to different loads, i.e. quasi-static/low velocity compression and indentation, ballistic impact, high speed compression and blast loading, are reviewed. The emphasis has been placed on their plastic deformation, failure and energy absorption behaviours.

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As concrete and mortar materials widely used in structural engineering may suffer dynamic loadings, studies on their mechanical properties under different strain rates are of great importance. In this paper, based on splitting tests of Brazilian discs, the tensile strength and failure pattern of concrete and mortar were investigated under quasi-static and dynamic loadings with a strain rate of 1–200 s−1. It is shown that the quasi-static tensile strength of mortar is higher than that of concrete since coarse aggregates weaken the interface bonding strength of the latter. Numerical results confirmed that the plane stress hypothesis lead to a lower value tensile strength for the cylindrical specimens. With the increase of strain rates, dynamic tensile strengths of concrete and mortar significantly increase, and their failure patterns change form a single crack to multiple cracks and even fragment. Furthermore, a relationship between the dynamic increase factor and strain rate was established by using a linear fitting algorithm, which can be conveniently used to calculate the dynamic increase factor of concrete-like materials in engineering applications.