NEW CONTINUOUS FATIGUE DAMAGE MODEL BASED ON WHOLE DAMAGE FIELD MEASUREMENT

First of all,the whole damage field curves with toughness that selected as the fatigue damage variable was measured,then on the basis of frame of nonlinear continuum fatigue damage theory,the expressive form of fatigue damage parameter was decided by means of the tested curve data,and a new nonlinear fatigue damage cumulative model was proposed.Comparison of the new nonlinear fatigue damage model with test results showed reasonably good agreement.Based on this comparison,formula of lifetime calculation on complex loading was derived and mean stress was considered by the formula of lifetime calculation.Experiment stated clearly that two loading prediction by means of this calculation model was quite reasonable.