TY - JOUR
T1 - Mixed mode fatigue crack propagation behaviour of aluminium F357 alloy
AU - Grasso, Marzio
AU - Xu, Yigeng
AU - Russo, Roberto
AU - Rosiello, Vincenzo
N1 - This document is the Accepted Manuscript version of the following article: Marzio Grasso, Yigeng Xu, Robert Russo, and Vincenzo Rosiello, ‘Mixed mode fatigue crack propagation behaviour of aluminium F357 alloy’, Engineering Failure Analysis, Vol. 90: 463-475, August 2018. Under embargo until 12 April 2019.
The final, definitive version is available online via: https://doi.org/10.1016/j.engfailanal.2018.04.010
PY - 2018/8/1
Y1 - 2018/8/1
N2 - Manufacturing defects are often not in the plane perpendicular to the loading direction and will propagate under mixed mode fatigue loading condition. This paper presents a numerical study of mixed mode crack growth behaviour in H-shaped specimens made of aluminium F357 alloy. The size and orientations of the crack are based on the fractographic observation of defects in F357 specimens manufactured by foundry. Equivalent values of the stress intensity factor (SIF) and the maximum circumferential tensile stress criterion have been adopted to simulate growth of cracks at angles of 90⁰, 60⁰ and 45⁰ to the loading direction, respectively. Mixed mode fatigue crack growth behaviours are analysed in terms of the shape of crack front, SIF variation, and kink angle. The mixity of SIFs of three modes is complex at early stage of growth with the maximum mode III SIF value at the two ends and the maximum mode II SIF value at the middle of the crack front. The crack surface rotates during the mixed mode crack growth, becoming normal to the loading direction regardless of the initial orientation of the crack. The simulated crack front agrees well with the final elliptical shape of the crack front observed in the physical test specimens. The initial crack orientated at 45 to the loading direction has the longest fatigue life compared with other two crack orientations.
AB - Manufacturing defects are often not in the plane perpendicular to the loading direction and will propagate under mixed mode fatigue loading condition. This paper presents a numerical study of mixed mode crack growth behaviour in H-shaped specimens made of aluminium F357 alloy. The size and orientations of the crack are based on the fractographic observation of defects in F357 specimens manufactured by foundry. Equivalent values of the stress intensity factor (SIF) and the maximum circumferential tensile stress criterion have been adopted to simulate growth of cracks at angles of 90⁰, 60⁰ and 45⁰ to the loading direction, respectively. Mixed mode fatigue crack growth behaviours are analysed in terms of the shape of crack front, SIF variation, and kink angle. The mixity of SIFs of three modes is complex at early stage of growth with the maximum mode III SIF value at the two ends and the maximum mode II SIF value at the middle of the crack front. The crack surface rotates during the mixed mode crack growth, becoming normal to the loading direction regardless of the initial orientation of the crack. The simulated crack front agrees well with the final elliptical shape of the crack front observed in the physical test specimens. The initial crack orientated at 45 to the loading direction has the longest fatigue life compared with other two crack orientations.
KW - Fatigue crack growth
KW - Linear elastic fracture mechanics (LEFM)
KW - Mixed-mode fatigue and fracture
UR - http://www.scopus.com/inward/record.url?scp=85046088107&partnerID=8YFLogxK
U2 - 10.1016/j.engfailanal.2018.04.010
DO - 10.1016/j.engfailanal.2018.04.010
M3 - Article
SN - 1350-6307
VL - 90
SP - 463
EP - 475
JO - Engineering Failure Analysis
JF - Engineering Failure Analysis
ER -