Author(s)

Brahmananda Pramanik, P. Raju Mantena

Department of Mechanical Engineering, University of Mississippi, Oxford, USA.
Department of Mechanical Engineering, University of Mississippi, Oxford, USA..

This paper presents an investigation on energy absorption characteristics of nano-reinforced panels, laminated face sheets and sandwich composites in high velocity ballistic and low velocity punch-shear experiments. The vinyl ester panels were reinforced with 1.25 and 2.5 wt. percent nanoclay and exfoliated graphite platelets. Three different face sheets were manufactured with E-glass, Owens Corning HP ShieldStrand^? glass and T-700 Carbon woven fabric in vinyl ester; and one with the E-glass and graphite platelets impregnated vinyl ester matrix. The sandwich composites were fabricated with balsa, PVC foam, 3D-fiber reinforced Tycor^? and fire resistant fly-ash based Eco-Core^? cores in between E-glass/vinyl ester face sheets. Ballistic tests were conducted according to NIJ level III using a universal receiver equipped with a barrel to launch 0.308 caliber M80 ball round projectile at about 890 m/s. Low velocity punch-shear tests were performed at around 3 m/s according to ASTM D3763 Standard using a drop-weight impact test system. The tortuosity of the fractured surface in nanocomposite specimens has been investigated using digital microscope. In ballistic tests, the 3-D fiber reinforced Tycor^? core provided the most resistance when projectile strikes at the web-flange interface region. The 2.5 wt. pct. graphite platelet reinforced nanocomposite, HP ShieldStrand^? glass vinyl ester face sheets, and E-glass/Eco-Core? sandwich composite showed the best energy absorption under low velocity punch-shear.

Energy Absorption, Tortuosity; Ballistic; Punch-Shear; Nanocomposites; Sandwich Composites

B. Pramanik and P. Mantena, "Energy Absorption of Nano-Reinforced and Sandwich Composites in Ballistic and Low-Velocity Punch-Shear," Open Journal of Composite Materials, Vol. 2 No. 3, 2012, pp. 87-96. doi: 10.4236/ojcm.2012.23010.