TY - GEN
T1 - Analysis of constant and variable amplitude strain-life data using a novel probabilistic Weibull regression model
AU - Pinto, Hernán
AU - De Jesus, Abílio M.P.
AU - Canteli, Alfonso Fernández
PY - 2010
Y1 - 2010
N2 - The relation between the total strain amplitude and the fatigue life measured in cycles is usually given as strain-life curves based on the former proposals of Basquin for the elastic strain-life and Coffin-Manson for the plastic strain-life. In this paper, a novel Weibull regression model, based on an existing well established Weibull model for the statistical assessment of stress-life fatigue data, is proposed for the probabilistic definition of the strain-life field. This approach arises from sound statistical and physical assumptions and not from an empirical proposal insufficiently supported, provides an analytical probabilistic definition of the whole strain-life field as quantile curves both in the low-cycle and high-cycle fatigue regions, deals directly with the total strain without the need of separating its elastic and plastic strain components, permit dealing with run-outs, and can be applied for probabilistic lifetime prediction using damage accumulation. The parameters of the model can be estimated using different well established methods proposed in the fatigue literature, in particular, the maximum likelihood and the two-stage methods. In this work, the proposed model is applied to analyze fatigue data, available for a pressure vessel material - the P355NL1 steel, consisting of constant amplitude, block and spectrum loading, applied to smooth specimens, previously obtained and published by authors. A new scheme to deal with variable amplitude loading in the background of the proposed regression strain-life Weibull model is described. The possibility to indentify the model constants using both constant amplitude and two-block loading data is discussed. It is demonstrated that the proposed probabilistic model is able to correlate the constant amplitude strain-life data. Furthermore, it can be used to correlate the variable amplitude fatigue data if the model constants are derived from two block loading data. The proposed probabilistic regression model is suitable for reliability analysis of notched details in the framework of the local approaches.
AB - The relation between the total strain amplitude and the fatigue life measured in cycles is usually given as strain-life curves based on the former proposals of Basquin for the elastic strain-life and Coffin-Manson for the plastic strain-life. In this paper, a novel Weibull regression model, based on an existing well established Weibull model for the statistical assessment of stress-life fatigue data, is proposed for the probabilistic definition of the strain-life field. This approach arises from sound statistical and physical assumptions and not from an empirical proposal insufficiently supported, provides an analytical probabilistic definition of the whole strain-life field as quantile curves both in the low-cycle and high-cycle fatigue regions, deals directly with the total strain without the need of separating its elastic and plastic strain components, permit dealing with run-outs, and can be applied for probabilistic lifetime prediction using damage accumulation. The parameters of the model can be estimated using different well established methods proposed in the fatigue literature, in particular, the maximum likelihood and the two-stage methods. In this work, the proposed model is applied to analyze fatigue data, available for a pressure vessel material - the P355NL1 steel, consisting of constant amplitude, block and spectrum loading, applied to smooth specimens, previously obtained and published by authors. A new scheme to deal with variable amplitude loading in the background of the proposed regression strain-life Weibull model is described. The possibility to indentify the model constants using both constant amplitude and two-block loading data is discussed. It is demonstrated that the proposed probabilistic model is able to correlate the constant amplitude strain-life data. Furthermore, it can be used to correlate the variable amplitude fatigue data if the model constants are derived from two block loading data. The proposed probabilistic regression model is suitable for reliability analysis of notched details in the framework of the local approaches.
UR - http://www.scopus.com/inward/record.url?scp=77953206241&partnerID=8YFLogxK
U2 - 10.1115/PVP2009-77531
DO - 10.1115/PVP2009-77531
M3 - Conference contribution
AN - SCOPUS:77953206241
SN - 9780791843680
T3 - American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP
SP - 457
EP - 467
BT - Proceedings of the ASME Pressure Vessels and Piping Conference 2009
T2 - 2009 ASME Pressure Vessels and Piping Conference, PVP 2009
Y2 - 26 July 2009 through 30 July 2009
ER -