Elastic–Plastic Behaviors of Vertically Aligned Carbon Nanotube Arrays by Large-Displacement Indentation Test

Abstract

AbstractThis chapter describes the large-displacement indentation test method for examining elastic–plastic behaviors of vertically aligned carbon nanotube arrays (VA-CNTs). The principle of this test is explained by using a cavity expansion model. The experiments have been performed on VA-CNTs synthesized by the chemical vapor deposition (CVD) method. Under a cylindrical, flat indenter, the VA-CNTs exhibit two distinct deformation stages: a short, elastic deformation at small displacement and a plateau-like, plastic deformation at large displacement. The critical indentation stress, a measure of yield stress or collapsing stress of the VA-CNT arrays, has been obtained. The deformation mechanism of the VA-CNTs at large displacement is revealed with scanning electronic microscope (SEM) images of the deformed VA-CNTs and finite element simulations.KeywordsLarge DisplacementSolid PolymerEquivalent Plastic StrainPlastic CollapseIndentation StressThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.