Analysis of the Tensile Strength of Copy Paper with a Center Notch Based on Four Strength Theories

Abstract

The tensile strength of a copy paper with a center notch was measured. During the test, the loading direction coincided with the cross direction (CD) or the machine direction (MD) of the paper sheet, and the configuration and dimension of the notch were varied. The relationship between the tensile strength and notch dimension was fitted using the following four theories: uniform stress criterion (USC), point stress criterion (PSC), average stress criterion (ASC), and fracture mechanics theory (FMT). Although the effect of loading direction was significant on the relationship between the tensile strength and notch dimension, the effect of notch configuration was not so significant. When the loading direction coincided with the CD of the paper, the PSC and ASC methods were superior to the other two methods for fitting the relationship. In contrast, the PSC and FMT methods were superior to the other two methods for fitting the relationship when the loading direction coincided with the MD.