Fatigue crack growth behavior of a titanium matrix composite under thermomechanical loading. Doctoral thesis

Thesis/Dissertation · Wed Dec 01 04:00:00 EST 1993

OSTI ID:200163

Blatt, P A

The crack growth characteristics of a 4-ply, unidirectional, titanium matrix composite, SCS-6/ti-6Al-2Sn4Zr-2Mo, subjected to thermomechanical fatigue were investigated. A linear summation model was developed to predict the isothermal and thermomechanical fatigue (TMF) crack growth rates of the composite. The linear summation approach assumes the total fatigue crack growth rate is a combination of a cycle-dependent and a time-dependent component. To assist the modeling effort, a series of isothermal, in-phase, and out-of-phase crack growth test were conducted. The test temperatures ranged from 15000 to 53800 and the fastest thermal frequency was 0.0083 Hz. With the excepton of the 15000 isothermal test, the model was able to correlate all the baseline fangue crack growth test data between oK of 50 to 9OMPa. In additon, the model was able to predict the fatigue crack growth rate of a proof test which involved a continual change in temperature range and load range to produce a constant crack growth rate. The proof test began under isothermal conditions at the maximum temperature and ended under in-phase TMF conditions.

• Research Organization: Wright Lab., Wright-Patterson AFB, OH (United States)
• OSTI ID: 200163
• Report Number(s): AD-A--299687/4/XAB; WL-TR--95-4078
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
CRACK PROPAGATION
DUCTILITY
MATRIX MATERIALS
MOLYBDENUM ALLOYS
REINFORCED MATERIALS
THERMAL FATIGUE
THERMAL STRESSES
TIN ALLOYS
TITANIUM ALLOYS
ZIRCONIUM ALLOYS