Creep Fracture Mechanics

We consider a homogeneous, isotropic body containing a crack and subjected to external loading. To this crack is associated the usual coordinate system. This body is of a creeping material.We present in succession the stress-and-strain singularities in the vicinity of the crack, which is at first stationary, and then moving. These singularities are described with the help of various loading parameters. Experimental correlation of initiation of extension and growth with these parameters are presented with their shortcomings. Then various relations between micromechanisms and macromechanics are given in the case of one controlling micromechanism and one creep law, which is the secondary-creep law. Finally, damage-continuum mechanics are presented.