Numerical analysis of projectile impact at isotropic layered plate

U radu se daje kratak uvod u osnovne podjele u području terminalne balistike te se prezentiraju pristupi kojima se rješavaju problemi u ovom području. Nakon toga, u drugom poglavlju je opisana problematika materijalnog modela u literaturi i teškoće s implementacijom materijalnog modela u Abaqus/Explicit. Validacija približnog modela provedena je paralelno sa razvojem simulacija i materijalnog modela te je s početne validacije pojedinačnih slučajeva proširena na validaciju na nizu balističkih krivulja za ploče različitih debljina. Nakon proširivanja materijalnog modela i uključivanja karakteristike plastičnog područja projektila, validacija materijalnog modela ploče je pokazala dovoljno dobro poklapanje sa eksperimentalnim krivuljama. Nakon validacije materijalnog modela, u trećem poglavlju su ispitani utjecaji na probijanje provođenjem niza simulacija. Utjecaj kuta udara projektila ispitan je nizom simulacija za slučajeve različitih kuteva udara projektila s ravnim vrhom u ploču debljine 16 mm. Utjecaj vrha projektila ispitan je nizom simulacija za slučajeve udara projektila s koničnim vrhom u ploču debljine 12 mm. Utjecaj konfiguracije mete ispitan je sa tri simulacije udara koničnog projektila u homogenu ploču i višeslojne konfiguracije mete sa i bez razmaka između ploča.A short introduction into the field of terminal ballistics and its characteristic criteria for classifying ballistic impacts is made. After that, in the second chapter, the material model found in the scientific articles is shown and the difficulties with implementing that material models into Abaqus/Explicit is explained. The process of validation of the approximate material model, as it is developed, is shown – from the validation on the individual impact cases to the validation on the series of ballistic limit curves for several target plate thicknesses. The validation of the material model was found sufficiently good after the adjustment of the projectile material model i.e. the inclusion of the plastic behaviour, was made. In the third chapter, a series of simulations were conducted in order to determine the main influences on the penetration. The influence of the obliquity was determined by a series of simulations where the blunt projectile impacted the 16 mm thick plate under different angles. The influence of the projectile nose shape was determined by a series of simulations where the conical projectile impacted the 12 mm thick plate. The influence of the target configuration was determined by three simulations where the conical projectile impacted the homogenous plate, the layered plate with no clearance between two plates and the layered plate with clearance between two plates