Energy Absorption of Nano-Reinforced and Sandwich Composites in Ballistic and Low-Velocity Punch-Shear

Brahmananda Pramanik,P Raju Mantena

doi:10.4236/ojcm.2012.23010

Abstract

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.

Highlights

This research is primarily focused on developing stronger, safer and more cost-effective structures for the new generation naval ships; especially nanoparticle reinforced glass/carbon polymeric based composites and structural sandwich composites for blast, shock and impact mitigation
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 transversely compressed poly-vinyl chloride (PVC) foam core was decompressed after ballistic penetration

Summary

Introduction

This research is primarily focused on developing stronger, safer and more cost-effective structures for the new generation naval ships; especially nanoparticle reinforced glass/carbon polymeric based composites and structural sandwich composites for blast, shock and impact mitigation. These blast resistant structures must endure the high stresses produced by shocks and ballistic, and low velocity impacts. Gama et al [1,2] and Xiao et al [3] performed quasistatic, ballistic and low velocity impact punch-shear tests to define the elastic and absorbed energies of composites as a function of penetration displacement. The impact load, displacement, energy plots and visual inspection of the post damaged specimen described the punch shear response and failure characteristics of these composites

Material Description

Experimentation

Results and Discussion

Conclusions