Title
Study of fatigue crack growth in al-mg-si alloys using a predictive model under positive and negative load ratios
Date Issued
01 January 2014
Access level
metadata only access
Resource Type
conference paper
Author(s)
Reis Pereira Baptista C.A.
da Silva Antunes A.M.B.
Pastoukhov V.
Torres M.A.S.
University of São Paulo
Publisher(s)
Trans Tech Publications
Abstract
The study of fatigue crack growth (FCG) is aimed at residual life estimations in order to apply the damage tolerant criterion. Usual approaches are based on semi-empirical models that consider the stress intensity factor range of fracture mechanics, DK, as the governing driving force for crack propagation. An alternative approach is the use of predictive theoretical schemes arising from damage mechanics. Although they haven't achieved a reliability level high enough to be used in design, predictive models may be important in some situations like material selection. In the present work, a predictive FCG method based on the cumulative damage of volume elements along the crack path is employed. The development of the work includes considerations about the stress distribution in the cracked body and the stress-life and strain-life relations used in the computational procedure. A previously developed analytical expression for the stress distribution ahead of the crack in a finite width plate, based on the numerical analysis performed by the Finite Element Method, is used in the predictive method. The stress field is determined for both upper and lower limits of cyclic loadings. The fatigue crack growth behavior of three Al-Mg-Si alloys: AA 6005, AA 6351 and AA 6063, tempered and aged for the T6 condition, were analysed for positive and negative R-ratios. In order to check the model results, constant amplitude FCG tests with load ratios ±0.5 were carried out in M(T) specimens. The experimental results, compared to the computational simulations, show that it is possible to obtain predictions of FCG behaviour for both positive and negative load ratios. © (2014) Trans Tech Publications, Switzerland.
Start page
1785
End page
1790
Volume
891-892
Language
English
OCDE Knowledge area
Ingeniería de materiales
Ingeniería, Tecnología
Subjects
Scopus EID
2-s2.0-84898918320
Resource of which it is part
Advanced Materials Research
ISSN of the container
10226680
ISBN of the container
9783038350088
Conference
11th International Fatigue Congress, FATIGUE 2014
Sources of information:
Directorio de Producción Científica
Scopus