Micromechanisms of fatigue crack growth at high stress

Advanced Methods of Fatigue Assessment

“…They can be overcome by using the cyclic crack tip opening displacement Dd t as crack driving force parameter which was proposed by many researchers, based on the previous application of d t by Wells under static loading conditions (Wells 1961;McEvily et al 1974;Tomkins 1975Tomkins , 1980Tanaka et al 1984;Brown et al 1988). They can be overcome by using the cyclic crack tip opening displacement Dd t as crack driving force parameter which was proposed by many researchers, based on the previous application of d t by Wells under static loading conditions (Wells 1961;McEvily et al 1974;Tomkins 1975Tomkins , 1980Tanaka et al 1984;Brown et al 1988).…”

On some criterial problems of fatigue crack initiation and growth in polycrystals

“…This conclusion contradicts numerous experimental findings, e.g., those reported in [14,17]. The fatigue macrocrack growth may occur also in the case where microcracks arise and propagate in the reversible elastoplastic deformation zone at the macrocrack tip [18].…”

“…This relationship has been confirmed for a series of materials at the second segment of the fatigue crack growth rate curve, when comparing the crack growth rate and the fatigue striation width proportional to δ, for example in [8,14,15,16]. These are usually the materials with fcc lattice, including austenitic steels.…”

“…The fatigue macrocrack growth by the LS-mechanism an also proceed through the crack tip blunting. This mechanism is considered to be the main one in [14]. Various modifications of the LS-mechanism have been proposed; noteworthy among them is the model which explains a complex profile of a fatigue crack in plastic materials [15,16].…”

Crack Growth Rate Model under Constant Cyclic Loading and Effect of Different Singularity Fields

“…In the intermediate K range, log(da/dN) is almost linearly related to log( K), hence the semi-empirical relation proposed by Paris and Erdogan, da/dN=C( K) m , where C and m are termed material constants. It is well-known that fatigue crack growth occurs because of local reversed plastic yielding of a material near the crack tip [1][2][3]. Based on nonlinear fracture mechanics and low cycle fatigue concepts, the crack growth law is desirable to be formulated and some attempts were made scholars.…”