織物SiC/SiC複合材料の破壊靭性評価手法

概要

論文の詳細を見る
It is well known that ceramic matrix composites (CMC) exhibit improved fracture toughness which is necessary for heat-resistant structural ceramics. In the presence of a sharp defect, however, the CMC show nonlinear and nonelastic behavior yield many microcracks around a main crack tip. A conventional fracture toughness evaluation approach applied to many kinds of metal, therefore, cannot be directly applied to the CMC. Although several approches have been applied to the CMC, a simple approach applicable to a damage resistant design of the CMC structure has not been established. In this study, fabric SiC/SiC composites were used to evaluate the fracture toughness. Two types of specimens were tested and an evalation method of the fracture toughness was investigated experimentally. It is shown that the fracture resistance curve and the fracture toughness as a material property can be evaluated in terms of a stress intensity factor using an equivalent crack length calculated from a compliance regarding the origin of a load-deflection curve.
一般社団法人日本機械学会の論文
1996-02-25