The Calculations of Evolving Rates Realized with Two of Type Variables in Whole Process for Elastic-Plastic Materials Behaviors under Unsymmetrical Cycle

On the basis of fatigue, damage and fracture accidents happened from engineering practices, based on data of references to research and analyze, research some mathematical methods in mechanics, adopt two types of variables a and D, combine program computing of computer, for elastic-plastic steels with short and long cracks, for their fatigue-damage-fracture behaviors put forward several calculations models, which are the crack growth rates and the damage evolving rates at each stage and in whole process; Also provide calculations methods about the two types of variables, some methods calculated in two stages or in whole process, and the conversion methods between the variables, between the equations and between the dimensional units; Indicate their physical and the geometrical meanings for some key parameters; Also give a calculation example about short crack and long crack growth rates and damage evolving rates in two stages. Thereby communicate each other the intersecting relations between their computing models and between the disciplines. This works for saving man powers and funds on fatigue-damage-fracture testing, promote applying of each discipline, it will be having practical significance.