ETD

Archivio digitale delle tesi discusse presso l'Università di Pisa

Tesi etd-09012022-110756


Tipo di tesi
Tesi di dottorato di ricerca
Autore
BOVECCHI, FEDERICO
URN
etd-09012022-110756
Titolo
Influence of engineered residual stresses on the fatigue properties of aluminium alloys: experimental and numerical investigations
Settore scientifico disciplinare
ING-IND/04
Corso di studi
INGEGNERIA INDUSTRIALE
Relatori
tutor Prof.ssa Boni, Luisa
relatore Prof. Fanteria, Daniele
Parole chiave
  • fatigue crack growth
  • corner crack
  • laser shock peening
  • cold expansion
  • shot peening
  • aluminium alloys
Data inizio appello
20/09/2022
Consultabilità
Non consultabile
Data di rilascio
20/09/2092
Riassunto
The present work adds to the state of the art by tackling the problem of fatigue with a double approach. First, an experimental approach with the aim of determining if an innovative technology, called laser shock peening, is more effective than the currently employed techniques --- shot peening and cold expansion --- in reducing the sensitivity of aluminium alloys to fatigue. Second, a numerical approach, based on linear elastic fracture mechanics and plasticity-induced crack closure, which exploits finite element simulations to study growth rate and shape evolution of corner cracks in three different scenarios of increasing complexity: open hole, pin-loaded hole, and cold-expanded pin-loaded hole. Regarding the numerical studies on fatigue propagation, simulation results are compared with experimental data and reveal that the adopted numerical strategy can simulate quite well both crack growth rate and front shape evolution in absence of residual stresses. On the other hand, with the introduction of residual stresses induced by cold expansion, the model yields extremely non-conservative fatigue crack propagation results.
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