Abstract:

Some important problems in fatigue fracture of metal materials and structures under complex loading conditions and corrosion environments are analyzed on the basis of three dimensional elastic plastic fracture theory and experimental data base. Special emphases are given on corrosion fatigue crack growth, which is shown to be independent of the stress ratio and geometry of specimens when represented by use of the three dimensional theory. It is also shown that the limited stress life curve of material with different initial defect sizes is in linear relation in the log log coordinates. The prediction of the whole fatigue life of structures and the calendar life of machines are discussed along this line.

Key words: three-dimensional fatigue fracture, corrosive fatigue, spectrum loading, service life