Journal Published Online: 01 January 1999
Volume 21, Issue 1

Residual Strength Degradation of Cross-Ply Titanium Matrix Composite Due to Elevated Temperature



This study investigates the residual strength degradation of cross-ply, SCS-6/Ti-15-3 titanium matrix composite (TMC) due to elevated temperature fatigue. To accomplish this, several specimens were cycled at 427°C to certain fractions of their expected fatigue lives, then monotonically loaded to failure. Fatigue tests were conducted in both load-control mode with a load ratio (Rσ) of 0.05 and strain-control mode with a strain ratio (Rε) of − 1. Maximum stresses in the load-controlled tests were 300 and 450 MPa with frequencies of 5 and 10 Hz, respectively. The strain amplitudes ranged from 0.25 to 0.4% in the strain-controlled tests. Rather than being conducted at a constant frequency, these tests were performed at a strain rate of 0.1% per s. Various mechanical responses during cycling are discussed and compared for the load-controlled and strain-controlled tests. After failure, specimens were sectioned and studied using both optical and scanning electron microscopy. Residual strength data were then correlated to the amount and type of each damage mechanism. It was found that the residual strength degradation in cross-ply laminate, when exposed to different fatigue conditions, correlates together with the fraction of the cyclic life left in the composite.

Author Information

Calcaterra, JR
AFIT/ENY, Wright-Patterson AFB, OH
Mall, S
AFIT/ENY, Wright-Patterson AFB, OH
Ruiz, A
AFIT/ENY, Wright-Patterson AFB, OH
Pages: 9
Price: $25.00
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Stock #: CTR10608J
ISSN: 0884-6804
DOI: 10.1520/CTR10608J