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MS Defense - Vincent Wu

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MSE MS Defense - Vincent Wu

Date/Time: Thursday, Dec 11th at 10:00 am

Location: 295 Love Bldg

Committee Members:

Dr. Christopher L. Muhlstein (Advisor, MSE)

Dr. Satish Kumar (MSE)

Dr. Meisha Shofner (MSE)

Title: Fatigue of Carbon Nanotube-loaded Polyacrylonitrile Fibers

 

Abstract:

The effects of loading polyacrylonitrile (PAN) single fibers with multi-walled carbon nanotubes (MWCNTs) on mechanical damage accumulation processes are explored in this thesis. Tensile, fatigue, and creep experiments were conducted to establish the effects of MWCNTs on the strength, ductility, fatigue lifetime, and viscoelastic/plastic (creep) damage accumulation. Three different configurations were tested: neat PAN fibers, PAN fibers loaded with 10 wt\% MWCNTs in the core, and PAN fibers loaded with 1.0 wt\% MWCNTs uniformly throughout. The tensile results yielded load and displacement data from which failure stress, failure strain, and elastic modulus were determined for all three fiber groups.  During stress-life fatigue tests (runout lives ~600,000 cycles) the fibers displayed similar fatigue susceptibilities. Longer lifetimes correlated with lower exerted stress amplitudes with roughly a factor of 2 difference in strength levels between the shortest and longest lifetimes. In spite of these similarities, the damage accumulation mechanisms are very sensitive to MWCNT loading. The loaded fibers displayed significant creep responses as compared to the unloaded neat fibers. This is in stark contrast to metal and ceramic-based composite fibers where the influence of nanotube loading on the matrix material is less pronounced.

 

Status

  • Workflow Status:
    Published
  • Created By:
    Danielle Ramirez
  • Created:
    12/05/2014
  • Modified By:
    Fletcher Moore
  • Modified:
    10/07/2016

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