Dynamic Mechanical Analysis and High Strain-Rate Energy Absorption Characteristics of Vertically Aligned Carbon Nanotube Reinforced Woven Fiber-Glass Composites

Kiyun Kim,Veera M Boddu,Seyed Soheil Daryadel,P Raju Mantena,Jignesh S Patel,Matthew W Brenner

doi:10.1155/2015/480549

Abstract

The dynamic mechanical behavior and energy absorption characteristics of nano-enhanced functionally graded composites, consisting of 3 layers of vertically aligned carbon nanotube (VACNT) forests grown on woven fiber-glass (FG) layer and embedded within 10 layers of woven FG, with polyester (PE) and polyurethane (PU) resin systems (FG/PE/VACNT and FG/PU/VACNT) are investigated and compared with the baseline materials, FG/PE and FG/PU (i.e., without VACNT). A Dynamic Mechanical Analyzer (DMA) was used for obtaining the mechanical properties. It was found that FG/PE/VACNT exhibited a significantly lower flexural stiffness at ambient temperature along with higher damping loss factor over the investigated temperature range compared to the baseline material FG/PE. For FG/PU/VACNT, a significant increase in flexural stiffness at ambient temperature along with a lower damping loss factor was observed with respect to the baseline material FG/PU. A Split Hopkinson Pressure Bar (SHPB) was used to evaluate the energy absorption and strength of specimens under high strain-rate compression loading. It was found that the specific energy absorption increased with VACNT layers embedded in both FG/PE and FG/PU. The compressive strength also increased with the addition of VACNT forest layers in FG/PU; however, it did not show an improvement for FG/PE.

Highlights

Development of novel, light-weight, high-strength, and hightemperature resistant materials has been the focus of increased research for many applications [1] such as aerospace and automobile structures, where the material experiences severe thermal gradients and requires high flexural rigidity and high vibration damping
The Dynamic Mechanical Analyzer (DMA) experiments were conducted on FG/PE, FG/PU, FG/PE/vertically aligned carbon nanotube (VACNT), and FG/PU/VACNT samples to compare and investigate effects of the embedded VACNT layers on specimens’ dynamic mechanical behavior
It was found that the average compressive strength of FG/PU/VACNT increased about 30% with respect to FG/PU

Summary

Introduction

Development of novel, light-weight, high-strength, and hightemperature resistant materials has been the focus of increased research for many applications [1] such as aerospace and automobile structures, where the material experiences severe thermal gradients and requires high flexural rigidity and high vibration damping. CNT can enhance the mechanical properties of FGM, due to their unique material properties, such as high stiffness, strength, and toughness [5, 6]. These nano-enhanced FGM are being considered for blast/ballistic protective structures and other armor applications. It was observed that VACNT based sandwich composites showed higher flexural rigidity and damping compared to samples consisting of carbon fiber fabric stacks without VACNT.

Methods

Results

Conclusion