Browsing by Author "Kuo, Jui-Ching"

Now showing 1 - 2 of 2

Organoclay effect on transverse compressive strength of glass/epoxy nanocomposites
(2006-11-01)
Tsai, Jia-Lin
;
Kuo, Jui-Ching
;
Hsu, Shin-Ming
;
機械工程學系
;
Department of Mechanical Engineering
This research focuses on the fabrication of glass fiber/epoxy nanocomposites containing organoclay as well as understanding the organoclay effect on the transverse compressive strength of nanocomposites. To demonstrate the organoclay effect, three different loadings of organoclay were dispersed, respectively, in the epoxy resin using a mechanical mixer followed by sonication. The corresponding glass/epoxy nanocomposites were produced by impregnating dry glass fiber with organoclay epoxy compound through a vacuum hand lay-up procedure. Unidirectional block specimens were employed for transverse compression tests on a hydraulic MTS machine. Experimental observations indicate that glass/epoxy nanocomposites containing organoclay exhibit higher transverse compressive strength than conventional composites. Furthermore, the failure mechanisms for all tested specimens were found to be fiber and matrix debonding. Therefore, results indicate that the increasing characteristic in transverse failure stress may be ascribed to the enhanced fiber/matrix adhesion modified by the organoclay.
Strain rate effect on out of plane shear strength of fiber composites
(2007)
Tsai, Jia-Lin
;
Kuo, Jui-Ching
;
機械工程學系
;
Department of Mechanical Engineering
This research aims to investigate strain rate effect on the out of plane shear strength of unidirectional fiber composites. Both glass/epoxy and graphite/epoxy composites were considered in this study. To demonstrate strain rate effect, composite brick specimens were fabricated and tested to failure in the transverse direction at strain ranges from 10(-4)/S to 700/s. Experimental observations reveal that the main failure mechanism of the specimens is the out of plane shear failure taking place on the plane oriented around 30 to 35 degree to the loading direction. The corresponding out-of-plane shear strength was obtained from the uniaxial failure stress through Mohr-Coulomb strength analysis. In addition, the associated shear strain rate on the failure plane was calculated through the coordinate transformation law. Results show that the out-plane shear strength increases with the increment of the shear train rates. A semi-logarithmic function expressed in terms of the normalized shear strain rate was employed to describe the rate dependence of the out-plane shear strength.