BALLISTIC LIMIT OF HIGH-STRENGTH STEEL AND AL7075-T6 MULTI-LAYERED PLATES UNDER 7.62-MM ARMOUR PIERCING PROJECTILE IMPACT

Abstract

THIS PAPER PRESENTS THE COMPUTATIONAL-BASED BALLISTIC LIMIT OF LAMINATED METAL PANELS COMPRISED OF HIGH STRENGTH STEEL AND ALUMINIUM ALLOY AL7075-T6 PLATE AT DIFFERENT THICKNESS COMBINATIONS TO NECESSITATE THE WEIGHT REDUCTION OF EXISTING ARMOUR STEEL PLATE. THE NUMERICAL MODELS OF MONOLITHIC CONFIGURATION, DOUBLE-LAYERED CONFIGURATION AND TRIPLE-LAYERED CONFIGURATION WERE DEVELOPED USING A COMMERCIAL EXPLICIT FINITE ELEMENT CODE AND WERE IMPACTED BY 7.62 MM ARMOUR PIERCING PROJECTILE AT VELOCITY RANGE OF 900 TO 950 M/S. THE BALLISTIC PERFORMANCE OF EACH CONFIGURATION PLATE IN TERMS OF BALLISTIC LIMIT VELOCITY, PENETRATION PROCESS AND PERMANENT DEFORMATION WAS QUANTIFIED AND CONSIDERED. IT WAS FOUND THAT THE MONOLITHIC PANEL OF HIGH-STRENGTH STEEL HAS THE BEST BALLISTIC PERFORMANCE AMONG ALL PANELS, YET IT HAS NOT CAUSED ANY WEIGHT REDUCTION IN EXISTING ARMOUR PLATE. AS THE WEIGHT REDUCTION WAS INCREASED FROM 20-30%, THE DOUBLE-LAYERED CONFIGURATION PANELS BECAME LESS RESISTANCE TO BALLISTIC IMPACT WHERE ONLY AT 20% AND 23.2% OF WEIGHT REDUCTION PANEL COULD STOP THE 950M/S PROJECTILE. THE TRIPLE-LAYERED CONFIGURATION PANELS WITH SIMILAR AREAL DENSITY PERFORMED MUCH BETTER WHERE ALL PANELS SUBJECTED TO 20-30% WEIGHT REDUCTIONS SUCCESSFULLY STOPPED THE 950 M/S PROJECTILE. THUS, TRIPLE-LAYERED CONFIGURATIONS ARE INTERESTING OPTION IN DESIGNING A PROTECTIVE STRUCTURE WITHOUT SACRIFICING THE PERFORMANCE IN ACHIEVING WEIGHT REDUCTION.