The blast and impact loading of aluminium foam

This paper reports results from impact and blast loading experiments on aluminium foam. The impact tests covered the velocity range required to induce non-uniform strain, and the propagation of a densification front through the specimen (often referred to as ‘shock’). In the direct impact tests, the velocity and test direction influenced the material response, with the stress tending to increase with velocity in the reverse direction. No significant increase in the stress was exhibited during the forward direction tests. This is in accordance with shock theory. Taylor test results confirmed the presence of shock in the foam specimens at impacts in excess of 60 m/s. For the blast tests, the impulse range produced by detonating plastic explosive did not result in shock loading of foam core cladding specimens. As strength enhancement due to shock may be undesirable in cladding structures due to the increased stress transfer to the protected structure, the cladding was considered acceptable.

► Impact and blast tests on aluminium foams were performed.
► Shock occurred above 40 m/s impacts.
► No shock was present in the blast tested cladding panels.
► Linear relationships between crush distance and impulse up to densification.