ABSTRACT
This chapter examines the physics of the interaction between blast-induced loading and vehicle and occupant response for both underbelly and side-blast attack of vehicles. It describes the basic phenomena of the blast flow-field loading conditions for air blast and discusses underbelly (UB) blast. The destructive power of explosives has been known since at least 220 BC; the first documented explosive accident injured early alchemists in China and led to the development of gunpowder. However, the fundamental scientific understanding of the underlying blast physics only really developed in earnest in the 1940s due to the need to understand the blast generated by the first nuclear weapons. UB blast loading is strongly influenced by various factors such as explosive type, charge standoff, size, shape, initiation, casing and fragmentation, soil conditions and burial depth. The hull armour of a vehicle has to withstand intense blast loading at high strain rates without rupture or excessive dynamic plate deformation into the crew survival space.
