CGR, An Improved Computerized Model to Predict Fatigue Crack Growth under Spectrum Loading,

A crack growth model which can be used to produce reasonably accurate predictions of crack growth under spectrum loading is presented. This model is contained in a computer program called CGR. The model was formulated through an evaluation and synthesis of the latest technology available for predicting crack propagation. An improved mathematical formulation was developed to solve the governing crack growth equations. Either the Paris or Forman equations are used to predict crack growth rates. A new method of integrating the crack growth equations over a block of constant load applications is used. Good, but limited, correlation between model predictions and experimental data has been obtained for both part-through and through-the-thickness cracks under spectrum loadings.