Creep fatigue damage under multiaxial conditions

Conference · Sat Jan 01 04:00:00 EST 1977

OSTI ID:7295090

Lobitz, D. W.; Nickell, R. E.

When structural components are subjected to severe cyclic loading conditions with intermittent periods of sustained loading at elevated temperature, the designer must guard against a failure mode caused by the interaction of time-dependent and time-independent deformation. This phenomena is referred to as creep-fatigue interaction. The most elementary form of interaction theory (called linear damage summation) is now embodied in the ASME Boiler and Pressure Vessel Code. In recent years, a competitor for the linear damage summation theory has emerged, called strainrange partitioning. This procedure is based upon the visualization of the cyclic strain in a uniaxial creep-fatigue test as a hysteresis loop, with the inelastic strains in the loop counter-balanced in one of two ways. The two theories are compared and contrasted in terms of ease of use, possible inconsistencies, and component life prediction. Future work to further test the damage theories is recommended. (TFD)

• Research Organization: Sandia Labs., Albuquerque, N.Mex. (USA)
• DOE Contract Number: EY-76-C-04-0789
• OSTI ID: 7295090
• Report Number(s): SAND-77-0296c; CONF-770807-3
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420200* -- Engineering-- Facilities
Equipment
& Techniques
CALCULATION METHODS
CREEP
FAILURES
FATIGUE
MECHANICAL PROPERTIES
MECHANICAL STRUCTURES
STRAINS