MODEL FOR PREDICTING EFFECT OF HOLE COLD EXPANDING ON INCREASING CRACK LIFE

The assessment of the increase of crack growth life after hole cold expanding is addressed. Tangential residual stress distribution around cold expanded hole is determined by combining theoretical calculation with experiment results. Radius of plastical zone is determined on the base of experimental results. Theoretical results of residual stress is modified with the relation between the largest residual stress and yield stress collected from measurement results of residual stress field. The method is examined with fatigue test results of cold expanded hole under constant amplitude spectrum.