Torsional failure analysis of C/SiC and SiC/SiC combined CMC torque tube

Abstract

To overcome the inherent limitations of the ceramic matrix composite (CMC) process and increase the torque capacity of CMC torque tubes, this study investigated the failure causes of 2D woven chemical vapor infiltration (CVI) C/SiC and SiC/SiC combined CMC torque tubes. The CT test was used to describe the non-homogeneous density distribution of the CMC torque tubes. Using the Archimedes drainage method to evaluate density and porosity, we simulated the stress distribution and failure strength of CMC torque tubes using an FEM model. Fixtures suitable for universal material testing apparatuses were used for CMC torque tube torsional tests. The stress-strain curves showed that two distinct fiber types of CMC torque tubes displayed different torsional tendencies, and we examined the main causes of failure. The SiC fiber in the CMC torque tube increased maximum shear stress and modulus. Additionally, the strength of the SiC/SiC torque tube, rather than the interface between the C/SiC and SiC/SiC torque tubes, was the primary cause of combined CMC torque tube failure.

Damage monitoring of SiC/SiC turbine blisk under overspeed rotation testing using X-ray computed tomography and natural frequency

“…9 It is necessary to develop damage detecting method to determine internal defects and damages in CMC components. 10,11,12 There are many types of nondestructive testing methods applied to the internal defects and environmental damage of CMCs, including X-ray computed tomography (XCT), 13 infrared thermal imaging, 14 microanalysis, 15 computed tomography (CT), 16 acoustic emission, 17,18 electrical resistance, 19 and ultrasonic. 20 The natural frequency is one of the main characteristics of vibration characteristics.…”