Investigating the impact of notch shapes on oxide–oxide ceramic matrix composites strength: A computational approach

Abstract

This study utilizes finite element analysis (FEA) to explore the effect of standardized notch shapes—triangular, circular, and rectangular on the tensile behavior of oxide–oxide (O–O) ceramic matrix composites (CMCs) across various temperature ranges. Findings reveal that unnotched samples exhibited a superior equivalent stress of ∼425 MPa, closely aligning with experimental values. However, under elevated temperatures of 1000°C and 1200°C, degradation occurs, reaching up to 54% decrease at 1200°C. Notched samples demonstrate similar behavior, with all notches acting as stress concentrators. Analysis of single and double notches highlights that circular notches have the most significant stress concentrators due to their smooth surfaces and lack of sharp edges, in contrast to rectangular and triangular notches. Although all notch types influence stress concentration, the absence of non-sharp corners in circular notches limit stress dissipation, resulting in higher stress concentrations. This trend persists under high temperature as well. The study emphasizes the critical need for a thorough assessment of notch effects, considering their position, orientation, shape, and size, as they significantly affect the mechanical properties of O–O CMCs.