Fatigue crack growth and closure through a tensile residual stress field under compressive applied loading

Fatigue crack growth and closure through a tensile residual stress field under an applied compressive loading is investigated by carrying out various applied stress ratio tests ranging from R = 0 to R = - ∞. It is found that even under applied compressive loading, fatigue crack growth rates are well correlated with the effective stress intensity factor range and the behavior of crack closure through a tensile residual stress field is uniquely controlled by an effective stress ratio which takes account of residual stresses. Consequently, the method of predicting fatigue growth rates can be successfully applied to crack growth through a tensile residual stress field. However, previoulsy used simple assumptions may lead to non-conservative estimates of crack growth rates.