Experimental and numerical investigations on the origins of the bodywork effect (k-effect)

This work is a continuation of previous research done to obtain qualitative and quantitative knowledge about the so-called bodywork effect or K-effect (from its German designation "Karroserie-efTekt"). The previously reported experimental data has been extended by determining the ballistic resistance of a Secure 500 high-hardness steel armor plate against the soft-core 5.56 x 45 mm Ml93 projectile, since the reported lowered ballistic resistance against this threat can be attributed to the same mechanisms as those causing the bodywork effect. The impact of the different projectiles on the armor plate was afterwards modeled using a finite element code. The simulated impacts showed good correspondence with the experimentally obtained results concerning ballistic limit velocity and plug morphology. The numerical results also confirmed the similarity between the effect of a flattened projectile tip for a hard steel projectile core and the easy flattening upon impact of a soft-core projectile.