Analysis of Bridging Stress Effect of Polycrystalline Aluminas Using Double Cantilever Beam Method II. Development of Double Cantilever Beam Method Considering Bridging Effect

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J. Korean Ceram. Soc. > Volume 33(5); 1996 > Article

Journal of the Korean Ceramic Society 1996;33(5): 590.

Double Cantilever Beam 방법을 이용한 다결정 알루미나의 Bridging 응력효과 해서 II. Bridging 효과를 고려한 Double cantilever Beam 분석방법의 정립

손기선, 이성학, 백성기

포항공과대학교 항공재료연구센터

Analysis of Bridging Stress Effect of Polycrystalline Aluminas Using Double Cantilever Beam Method II. Development of Double Cantilever Beam Method Considering Bridging Effect

ABSTRACT

This study aims at developing the double cantilever beam (DCB) method in order to calculate the bridging stress distribution in polycrystalline aluminas with different grain sizes. In the already existing DCB methods the measured crack opening displacement (COD) in coarse-grained aluminas deviates generally from the calcula-ted one because of the grain-interface bridging in the crack wake. In the current DBC method developed in the present study the effect of the bridging stress was considered in the DCB analysis. whereas the only effect of applied point-loading at the end of DCB specimen was taken into account in the existing DCB analysis The crack closure due to bridging stress was calculated using the power-law relation and the theoretical model developed in Part I of the present paper as bridging stress function and then compared analytically. The limitations of the current DCB methods such as specimen dimensions applied loads and elastic modulus were discussed in detail to provide a reliability of the newly developed DCB analysis for the bridging stress distribu-tion in polycrystalline aluminas.

Key words: Double cantilever beam(DCB), Polycrystalline alumina, Grain-interface bridging, Bridging stress, Crack opening displacement (COD), Crack closure