The electrical response of toughened nanocomposites subjected to quasi static and dynamic loading.

摘要

The purpose of this study was to investigate the electrical response of toughened nanocomposites subjected to quasi-static and dynamic loading. Carbon nanotubes (CNTs) have been extensively researched and found to have exceptional mechanical and transport properties. Carbon nanotubes were used to form a sensory network inside of an epoxy matrix. The electrical response of the material was correlated to the deformation and damage in the nanocomposite. The CNT composites utilized an epoxy matrix toughened by rubber and/or cenospheres. The cenospheres and rubber changed the material's mechanical properties and effected the formation of the CNT network. This had an impact on the electoral response of the sensory network.;Experimental specimens of Epoxy/CNT nanocomposite were made by loading epoxy resin with CNT. CNTs tend to agglomerate so in order to create a well dispersed network of CNT, the epoxy resin and CNT were subjected to ultrasonication and shear mixing. A vacuum chamber was used to remove any air bubbles and moisture from the composite. Cenospheres or liquid rubber were shear mixed into the resin to enhance the nanocomposites mechanical properties. The CNT/Epoxy specimens were then poured into a mold, allowed to cure and machined to standard testing dimensions.;Quasi static loading of specimens was done by an Instron 5585 and stress/strain data was recorded by the Instron software. The specimen's electrical resistance was recorded before the loading and used as a baseline. The electrical resistance was also recorded by a 4 point probe system as the specimens were loaded.;High strain rate testing was performed with an Instron Dynatup 9210 drop weight tower (strain rate 102). The specimen's electrical response was again recorded by a 4 point probe system. Real time damage and deformation of the specimens was recorded by a Phototron SA 1 high speed camera.