Threshold condition and rate of fatigue crack growth appear to be significantly affected by the degree of deflection of cracks. In the present paper, the reduction of the fatigue crack growth rate for a so-called `periodically-kinked crack' as compared to that for a straight counterpart is quantified via the Paris-Erdogan law modified according to some simple theoretical arguments. It is shown that such a reduction increases as the value of the kinking angle increases. Then, a so-called `continuously-kinked crack' (the kink length tends to zero) is considered and modelled as a self-similar invasive fractal curve. The sequence of kinking angles in the crack is such that the fatigue crack path is 'on average' straight. Using the Richardson's expression for self-similar fractals, the fractal dimension of the crack is expressed as a function of the kinking angle. It is shown that the fatigue crack growth rate in the Paris range depends not only on the above fractal dimension and in turn on the kinking angle, but also, in an explicit fashion, on the crack length. Some experimental results related to concrete and showing a crack size effect on the fatigue crack growth rate are analysed.

Influence of the crack morphology on the fatigue crack growth rate: a continuously-kinked crack model based on fractals / Carpinteri, Andrea; Spagnoli, Andrea; Vantadori, Sabrina; Danilo, Viappiani. - In: ENGINEERING FRACTURE MECHANICS. - ISSN 0013-7944. - 75:3-4(2008), pp. 579-589. [10.1016/j.engfracmech.2007.05.007]

Influence of the crack morphology on the fatigue crack growth rate: a continuously-kinked crack model based on fractals.

CARPINTERI, Andrea;SPAGNOLI, Andrea;VANTADORI, Sabrina;
2008-01-01

Abstract

Threshold condition and rate of fatigue crack growth appear to be significantly affected by the degree of deflection of cracks. In the present paper, the reduction of the fatigue crack growth rate for a so-called `periodically-kinked crack' as compared to that for a straight counterpart is quantified via the Paris-Erdogan law modified according to some simple theoretical arguments. It is shown that such a reduction increases as the value of the kinking angle increases. Then, a so-called `continuously-kinked crack' (the kink length tends to zero) is considered and modelled as a self-similar invasive fractal curve. The sequence of kinking angles in the crack is such that the fatigue crack path is 'on average' straight. Using the Richardson's expression for self-similar fractals, the fractal dimension of the crack is expressed as a function of the kinking angle. It is shown that the fatigue crack growth rate in the Paris range depends not only on the above fractal dimension and in turn on the kinking angle, but also, in an explicit fashion, on the crack length. Some experimental results related to concrete and showing a crack size effect on the fatigue crack growth rate are analysed.
2008
Influence of the crack morphology on the fatigue crack growth rate: a continuously-kinked crack model based on fractals / Carpinteri, Andrea; Spagnoli, Andrea; Vantadori, Sabrina; Danilo, Viappiani. - In: ENGINEERING FRACTURE MECHANICS. - ISSN 0013-7944. - 75:3-4(2008), pp. 579-589. [10.1016/j.engfracmech.2007.05.007]
File in questo prodotto:
File Dimensione Formato  
08 EFM CP06 Vol.75, No.3-4, 579-589 fractal.pdf

non disponibili

Tipologia: Documento in Post-print
Licenza: NON PUBBLICO - Accesso privato/ristretto
Dimensione 203.81 kB
Formato Adobe PDF
203.81 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

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/11381/1666142
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 42
  • ???jsp.display-item.citation.isi??? 42
social impact