Relaxation of residual stresses at cold-worked fastener holes due to fatigue loading

Ozdemir A., Edwards L.

FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES, cilt.20, sa.10, ss.1443-1451, 1997 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 20 Sayı: 10
  • Basım Tarihi: 1997
  • Doi Numarası: 10.1111/j.1460-2695.1997.tb01501.x
  • Dergi Adı: FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED)
  • Sayfa Sayıları: ss.1443-1451
  • Anahtar Kelimeler: residual stresses, cold expanded holes, fatigue crack growth, stress relaxation, EXPANDED HOLES
  • Gazi Üniversitesi Adresli: Evet

Özet

Cold-expansion of Fastener holes is now commonly used within the aerospace industry to increase the fatigue endurance of airframes. Although a number of methods of cold expansion are possible, the split-sleeve cold-expansion process is the most widely accepted and is frequently used in the repair and manufacture stages of both military and civil aircraft. In the present work, the redistribution of residual hoop stresses due to the application of constant amplitude fatigue loading at 4% cold-expanded holes has been studied. A modified Sachs method was adopted to evaluate the residual stress profiles and a replication technique was used to quantify crack growth. It was found that the decay of the residual hoop stress profile near the bore of the hole was due to the initiation and growth of small fatigue cracks. Cracks were found to initiate both near and below the fatigue limit, but subsequently arrested so stabilising the overall residual stress profile.