FATIGUE DAMAGE REPAIR - A COMPARISON OF SOME POSSIBLE METHODS

When a fatigue crack is discovered in an engineering component, some e xpeditious temporary repair may be needed before more thorough treatme nt is available. Conventional repair methods, such as grinding removal of the crack and stop drilling, are often employed. In this work, the method of drilling crack-flank holes near to but not at the crack tip has been studied. It was found that retardation still occurred. Moreo ver, if the holes were drilled a small distance ahead of the tip, the crack was likely to grow into the hole, achieving a considerable amoun t of life extension. The effects of inducing artificial crack closure by infiltrating epoxy resin, alumina powder and a mixture of both have also been investigated. These were compared with the effect of overlo ad-induced retardation. In all the methods studied, different degrees of crack growth retardation have been achieved, and they have the pote ntial to be developed into practical fatigue crack repair methods. Cop yright (C) 1996 Elsevier Science Limited.