TY  - JOUR
SN  - 0142-1123
N2  - In this paper, a mathematical model based on dimensional analysis and incomplete self-similarity is proposed for the interpretation of the grain size and loading frequency effects on the Paris and Wöhler regimes in metals. In particular, it is demonstrated that these effects correspond to a violation of the physical similitude hypothesis underlying the simplest Paris? and Wöhler power-law fatigue relationships. As a consequence, generalized representations of fatigue have to be invoked. From the physical point of view, the incomplete similarity behaviour can be regarded as the result of the multiscale character of the problem, where the crack length and the grain size are the two length scales interacting together. Moreover, it will be shown that the relationship between strength and grain size (Hall?Petch relationship) has also to be considered in order to consistently interpret the two opposite effects of the grain size on the Paris and Wöhler regimes within a unified framework. The incomplete similarity exponents are suitably quantified according to experimental results for Aluminum, Copper, Titanium and Nickel. The derived scaling laws are expected to be of paramount importance today, especially after the advent of ultra fine grained materials that offer unique mechanical properties owing to their fine microstructure. 
TI  - A dimensional analysis interpretation to grain size and loading frequency dependencies of the Paris and Wöhler curves 
AV  - none
KW  - Dimensional analysis; Fatigue crack growth; Grain size;   Loading frequency; Ultra fine grained materials
UR  - http://www.sciencedirect.com/science/article/pii/S0142112310002367
ID  - eprints1994
EP  -  483
A1  - Plekhov, Oleg
A1  - Paggi, Marco
A1  - Naimark, O.
A1  - Carpinteri, Alberto
PB  - Elsevier
SP  - 477 
Y1  - 2011///
JF  - International Journal of Fatigue
IS  - 3
VL  - 33
ER  -