Blast Performance of Sandwich Composites with Functionally Graded Core

Sandwich structures have important applications in the naval and aerospace industry, especially when they are subjected to high-intensity impulse loadings such as air blasts. During this event, the core materials play a vital role in the dynamic behavior of the sandwich structure. Since the material properties of a functionally graded/layered core can be designed and controlled, they show great potential to be an effective core design for absorbing the blast energy and improving the overall blast response of the sandwich structure. In this paper, an experimental investigation focuses on the blast resistance of sandwich composites with a functionally graded foam core subjected to shock wave loading. Four types of sandwich composites with a foam core graded/layered based on monotonically increasing the core layer wave impedance, while varying the number of core layers, have been studied. The experimental results show that monotonically increasing the core layer wave impedance while increasing the number of core layers, greatly reduces the wave impedance mismatch between consecutive layers and improves the overall blast resistance of the structure.