Techniques for High Temperature Fatigue Testing

High Temperature Fatigue Crack Propagation in INCONEL718

Ultrasonic Thermometer for High Temperature Materials Testing

This past year there were a total of 14 faculty members involved in 40 sponsored research projects. Sponsors included government agencies, navy labs and industry. In addition to the sponsored faculty research there were 15 midshipmen involved in independent research projects with faculty, four of which were Bowman Scholars. Many of these projects were also funded by outside sponsors. Overall, 2...

Fatigue testing of three peristernal median sternotomy closure techniques

BACKGROUND Failure of a sternotomy closure because of closure system fatigue is a complication that may result in dehiscence and put the individual at risk for serious complications. The purpose of this study was to assess the fatigue performance of three peristernal median sternotomy closure techniques (figure-of-eight stainless-steel wires, figure-of-eight stainless-steel cables, or Pectofix ...

Development of Ultrasonic Fatigue for Rapid, High Temperature Fatigue Studies in Turbine Engine Materials

A system for ultrasonic fatigue testing at temperatures as high as 700 C and at positive mean stresses has been developed. Its use is demonstrated by examining the fatigue behavior in the lifetime range of 10 to 10 cycles for the nickel-base superalloy Rene' 88 DT at 20 and 593 C for a load-ratio of 0.05. Crack initiation occurred from large grains and from inclusions, consistent with crack ini...

Fatigue Testing

Fatigue is the progressive, localized, permanent structural change that occurs in materials subjected to fluctuating stresses and strains that may result in cracks or fracture after a sufficient number of fluctuations. Fatigue fractures are caused by the simultaneous action of cyclic stress, tensile stress and plastic strain. If any one of these three is not present, fatigue cracking will not i...