New aluminium structure improves impact protection
A cheap and simple structure made of aluminium and designed to withstand the impact of offensive projectiles has been jointly developed by the Norwegian University of Science and Technology’s Structural Impact Laboratory (SIMLab) and the Norwegian Defence Estates Agency (NDEA).
Lighter and easier to move than steel or concrete, the aluminium double-panel design can be filled with any readily available substance – such as gravel or sand – and then pieced together using a click-together system and mounted in a retaining structure, such as a containing wall. Once the panel is in place it can be filled with the weight, which can be drained out of the bottom when the panel needs moving.
“These filled aluminium shapes can stand against projectiles and explosives,” says Tore Børvik, from the NDEA.
The new design could better protect military personnel, vehicles and buildings in battlefield scenarios. “We have developed a light, cheap and flexible solution to protect fences, buildings, ammunition dumps and containers”, says SIMLab’s leader, Magnus Langseth.
Each panel is constructed from aluminium shapes with cavities inside them, shaped by internal division walls. The panels are easy to produce by extruding them to create the internal cross-section.
The system was tested in a full-scale explosion. A container protected by SIMLab's aluminium panels sustained only minor damage from an explosion equivalent to four tonnes of TNT detonated from 120 metres away. Without the panels in place, the container would almost certainly have been destroyed.
Other tests have further borne out the panels' impact resistance: the accompanying image at the head of this story shows a projectile fired directly at the panel. The projectile has been prevented from penetrating all three layers of the panel's internal walls, even without the addition of any absorptive material.
SIMLab has now been invited to join an international co-operative effort comprised of the world’s leading researchers in mechanics and materials, where the theme is protection of vehicles in war zones. Further research on the aluminium panels continues.
NTNU's Structural Impact Laboratory (SIMLab) stated objective is the development of safe and cost-effective structures in aluminium, high-strength steels and polymers through advances in research areas such as materials, solution techniques and structures.
SIMLab has a particular focus on developing methods and tools for the virtual product development of structures exposed to impact and collisions. It currently works with partners including SINTEF, Hydro Aluminium and car manufacturers BMW, Audi and Renault, as well as the Norwegian Defence Estates Agency (NDEA).