TY - JOUR
T1 - Weibull modeling of the fatigue life for steel rebar considering corrosion effects
AU - Lan, Chengming
AU - Bai, Nani
AU - Yang, Haitao
AU - Liu, Caiping
AU - Li, Hui
AU - Spencer, B. F.
N1 - Funding Information:
This study is financially supported by the National Key R&D Program of China (Grant No. 2017YFC0806100 ), the NSFC project (Grant No. 51478039 ), Beijing Nova Program (Grant No. Z151100000315053 ), the Program of International S&T Cooperation (Grant No. 2015DFG82080 ), the Fundamental Research Funds for the Central Universities of China (Grant No. FRF-TP-15-001C1 ), the CSC Scholarship (No. 201606465033 ) and the Ningbo Science and Technology Project (No. 2015C110020 ).
Publisher Copyright:
© 2018 Elsevier Ltd
PY - 2018/6
Y1 - 2018/6
N2 - Corrosion of steel rebar is one of the most severe causes in the deterioration of RC (reinforced concrete) structures. This paper studies the influences of corrosion on fatigue life of steel reinforcement in RC structures. First, a Weibull model of the C-S-N (Corrosion S-N) relationship for steel rebar is proposed in this research. The corrosion degree and stress range are regarded as the input variables for the proposed Weibull model. The expectation–maximization (EM) algorithm is used to deal with parameter estimation considering the censored data. Fatigue data are collected from experiments reported in the literature for three types of corroded steel rebar, considering different corrosion processes. These data are then used to establish and validate the proposed model, and the influence of corrosion on fatigue life is illustrated and discussed in detail. The proposed multi-parameter phenomenological Weibull model can be used to evaluate the fatigue life of steel rebar for both natural corrosion and artificially accelerated corrosion, which establishes quantitative influences of corrosion degree on fatigue life for steel rebar. In particular, the results indicate that the influence of corrosion on fatigue life is not the same for different kinds of steel rebar. For example, the model shows that the fatigue life of Grade 500 MPa steel rebar, which is used widely in modern structures, is shown to be sensitive to corrosion; fatigue life decreases sharply once corrosion initiates. Moreover, the effect is more pronounced at lower stress ranges. Therefore, to prevent premature fatigue induced failures, avoiding corrosion in Grade 500 MPa steel rebar during the structural service period is crucial.
AB - Corrosion of steel rebar is one of the most severe causes in the deterioration of RC (reinforced concrete) structures. This paper studies the influences of corrosion on fatigue life of steel reinforcement in RC structures. First, a Weibull model of the C-S-N (Corrosion S-N) relationship for steel rebar is proposed in this research. The corrosion degree and stress range are regarded as the input variables for the proposed Weibull model. The expectation–maximization (EM) algorithm is used to deal with parameter estimation considering the censored data. Fatigue data are collected from experiments reported in the literature for three types of corroded steel rebar, considering different corrosion processes. These data are then used to establish and validate the proposed model, and the influence of corrosion on fatigue life is illustrated and discussed in detail. The proposed multi-parameter phenomenological Weibull model can be used to evaluate the fatigue life of steel rebar for both natural corrosion and artificially accelerated corrosion, which establishes quantitative influences of corrosion degree on fatigue life for steel rebar. In particular, the results indicate that the influence of corrosion on fatigue life is not the same for different kinds of steel rebar. For example, the model shows that the fatigue life of Grade 500 MPa steel rebar, which is used widely in modern structures, is shown to be sensitive to corrosion; fatigue life decreases sharply once corrosion initiates. Moreover, the effect is more pronounced at lower stress ranges. Therefore, to prevent premature fatigue induced failures, avoiding corrosion in Grade 500 MPa steel rebar during the structural service period is crucial.
KW - Corrosion
KW - Fatigue
KW - Probabilistic C-S-N surface
KW - Steel rebar
KW - Weibull modeling
UR - http://www.scopus.com/inward/record.url?scp=85042076172&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85042076172&partnerID=8YFLogxK
U2 - 10.1016/j.ijfatigue.2018.02.009
DO - 10.1016/j.ijfatigue.2018.02.009
M3 - Article
AN - SCOPUS:85042076172
SN - 0142-1123
VL - 111
SP - 134
EP - 143
JO - International Journal of Fatigue
JF - International Journal of Fatigue
ER -