Abstract:
In this research, a numerical investigation is reported in finding out the ballistic limit velocities of various sandwich structures when subjected to high speed impact. Composite Armor structures consisting of Thermoplastic Polyurethane core and Aluminum AA 5083 – H116 face-sheets were studied to find out their ballistic limit velocities, perforation and penetration resistance. The dynamic response of the sandwich structures was investigated using finite element analysis package ABAQUS/EXPLICIT. The geometrical nonlinearities were considered for both the materials. The Aluminum face-sheets were modelled using Johnson-Cook’s Material model while the TPU foam core was modelled using Ductile damage with Damage evolution model. Aluminum AA5083-H116 face skins were used as face skins with TPU cores of varying thicknesses to enhance the impact penetration and perforation resistance of sandwich structures. Increasing the thickness of face sheets and Core served to increase the impact and damage resistance. Increasing the thickness of face sheets from 1.2 mm to 1.5 mm and 2 mm thicknesses can enhance the ballistic resistance of structure up to 11.7% and 18.2%, respectively. By increasing the core thickness from 20 mm to 30 mm and 50 mm , ballistic resistance can be enhanced up to 30.6% and 40.8%, respectively. Target configuration, material parameters, projectile nose shape and impact velocity are some of the key factors that influence the ballistic response of the structure. The numerical methodology is found to be more efficient and reliable in the prediction of ballistic limit velocities and damage resistance of composite armor structures with more accurate results and this surely can replace the time consuming and expensive dynamic experiments.
