STRESS INTENSITY FACTORS AND FATIGUE LIFE OF BEAMS IN REVERSED BENDING

Two problems concerning the propagation of transverse cracks through b eams are studied with a crack modelled as a distribution of dislocatio ns. The first consists of a surface breaking normal crack present in r eversing bending, where it is shown that for deep cracks two cycles of loading are experienced for each cycle of applied load. The second is an initially buried normal crack, where stress intensity factors affe cting propagation both towards the surface and into the beam are evalu ated. The effect on the life of each of these components is then consi dered for a representative material.