Combining the weakest-link theory with fatigue crack growth modeling, this study presents a mechanical-probabilistic modeling of specimen size effect for 30NiCrMoV12 steel in a low cycle fatigue (LCF) regime. Particularly, the influence of specimen size on fatigue life is quantified by experiments in strain-controlled fatigue and crack propagation. Experimental results from replica tests with three geometrical specimens indicate that nearly all of its fatigue life consists of multiple surface cracking with mutual interactions and coalescences. A probabilistic procedure for multiple surface fracture simulation is then established by incorporating random processes of crack formation, propagation and coalescence between dispersed surface cracks. Moreover, an evaluation of surface damage evolution is elaborated based on statistical physics for different structural sizes/volumes, which showed good agreement between analytical life distributions and test results.

Evaluation of size effect on strain-controlled fatigue behavior of a quench and tempered rotor steel: Experimental and numerical study

Foletti, Stefano;Beretta, Stefano
2018-01-01

Abstract

Combining the weakest-link theory with fatigue crack growth modeling, this study presents a mechanical-probabilistic modeling of specimen size effect for 30NiCrMoV12 steel in a low cycle fatigue (LCF) regime. Particularly, the influence of specimen size on fatigue life is quantified by experiments in strain-controlled fatigue and crack propagation. Experimental results from replica tests with three geometrical specimens indicate that nearly all of its fatigue life consists of multiple surface cracking with mutual interactions and coalescences. A probabilistic procedure for multiple surface fracture simulation is then established by incorporating random processes of crack formation, propagation and coalescence between dispersed surface cracks. Moreover, an evaluation of surface damage evolution is elaborated based on statistical physics for different structural sizes/volumes, which showed good agreement between analytical life distributions and test results.
2018
Crack coalescence; Fatigue; Life prediction; Size effect; Weakest-link theory; Materials Science (all); Condensed Matter Physics; Mechanics of Materials; Mechanical Engineering
File in questo prodotto:
File Dimensione Formato  
scale_effect_LCF_MSEA.pdf

Accesso riservato

: Publisher’s version
Dimensione 5.95 MB
Formato Adobe PDF
5.95 MB Adobe PDF   Visualizza/Apri
11311-1078132_Foletti.pdf

accesso aperto

: Post-Print (DRAFT o Author’s Accepted Manuscript-AAM)
Dimensione 6.57 MB
Formato Adobe PDF
6.57 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11311/1078132
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 57
  • ???jsp.display-item.citation.isi??? 53
social impact