METHOD OF DECELERATING GROWTH OF NON-THROUGH FATIGUE CRACKINGS IN ARTICLE Russian patent published in 1994 - IPC

FIELD: aircraft technique. SUBSTANCE: method of decelerating growth of fatigue cracking in articles comprises steps of drilling openings in an apex of a cracking at both sides of outlet of a non-through cracking onto a surface of a part; drilling additional openings at both sides of a plane of the cracking, being symmetrical one relative to another and spaced by the same distance from the openings of the apex of the crackings; performing dynamic mutual displacement of boundaries of fatigue crackings; smoothly removing dynamic loads; placing mounting members in the openings, bracing them pairwise in planes, passing simultaneously through the openings of the cracking apex portions and through openings, arranged in a mean portion of the crackings, with subsequent tightening of the mounting members; ironing surfaces of the openings near apex of crackings before placing the mounting members; providing surface plastic deformation in the openings, in edges and along surface of the part at both sides in a plane of growth of crackings and before their apex in a zone of the cracking plane elongation; placing in the openings near the apex portions two half-sleeves, oriented by their interface normally relative to the plane of the cracking; arranging the mounting member in the openings, provided by the half-sleeves, with a radial tension in the plane of the cracking; pairwise bracing the mounting members at side of a rear surface of the part in two mutually parallel planes, passing through the openings near apex portions of the crackings and through the opening, being nearest to the mean portion of the cracking, and also in a plane, passing through the openings, remained free in the mean portion of the cracking. Such operations allow to provide uniform field of remaining compression stresses, increasing time period of delaying of fatigue cracking development. EFFECT: increased service period of articles. 1 cl, 1 tbl, 3 dwg