Experimental and analytical investigation into large ductile transverse deformation of monolithic and multi-layered metallic square targets struck normally by rigid spherical projectile

• The response of metallic square targets is studied experimentally and analytically.
• The monolithic and multi-layered targets are struck by rigid spherical projectile.
• The experiments have been carried out by a single stage gas gun impact test apparatus.
• By assuming an exponential transverse deformation, a new analytical model is derived.
• A modification to kinetic energy is created by assuming a localized distribution for impact velocity.
• The analytical results have acceptable consistency with experimental ones.

This paper introduces an experimental and analytical investigation of the large ductile transverse deformations of monolithic and multi-layered metallic square targets made of either aluminum alloy or mild steel or a combination of these materials struck normally by rigid spherical projectile. The experiments have been carried out by a single stage gas gun impact test apparatus and 25.1 g hard steel projectile with different velocities ranging from 42 to 158 m/s. By assuming an exponential transverse deformation shape function, a new analytical model is derived based on energy method and upper bound solution. A modification to the applied kinetic energy is created by assuming a localized distribution for initial impact velocity which provides quantitatively and qualitatively better analytical results and have acceptable consistency with experimental ones. The analytical results show that 15 out of 62 data are located on solid line, where the experimental and analytical values of final displacement are equaled. Also, 98% of data are set in the reliable range.