Residual Strength after Fatigue of Unidirectional and Cross-Ply Metal MatrixComposites at Elevated Temperature

摘要

This study investigated the residual strength of the unidirectional and cross-plylaminates of SCS-6 / Ti-15-3, metal matrix composite at elevated temperature 427 deg C (800 deg F) after under tension-tension load controlled mode. For this purpose, several specimens were fatigued to various fractions of the fatigue life and then loaded monotonically to failure. The purpose of this study was to determine the effects of different levels of fatigue damage on the composite's strength. The unidirectional specimens were cycled at a 900 MPa maximum stress at a frequency of 10 Hz, while, the cross-ply specimens were tested at both 300 MPa and 450 MPa at 5 Hz and 10 Hz, respectively. The residual strength results for the three cases showed similar trends in that residual strength drop with cycles was small until near the end of the fatigue life. Both the unidirectional and cross-ply specimens demonstrated only a small drop of the residual strength with cycles until near the end of the fatigue life. (Author).