A COMBINED EXPERIMENTAL AND ANALYTICAL INVESTIGATION OF CREEP DAMAGE DEVELOPMENT IN COPPER

A continuum damage mechanics (CDM) model was used to predict the devel opment and distribution of creep damage in triaxially stressed regions of oxygen-doped copper samples at 500-degrees-C based on uniaxial cre ep tests performed on that same material. Axisymmetrically notched sam ples of oxygen-doped copper were subjected to slow, constant-displacem ent-rate tensile testing at 500-degrees-C and interrupted after variou s test times. High resolution synchrotron radiography was used to imag e the creep damage in the samples. The experimentally measured creep d amage was then compared to the predictions from the continuum damage m echanics modeling for the same two sample geometries. The experimental ly determined distribution of creep damage correlates very well with t he model if the growth of damage is assumed to be controlled primarily by the maximum principal stress. Therefore, the growth of creep damag e in oxygen-doped copper under the imposed stress conditions occurs by a diffusive mechanism.