Analysis of constant and variable amplitude strain-life data using a novel probabilistic Weibull regression model

Hernán Pinto, Abílio M.P. De Jesus, Alfonso Fernández Canteli

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


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.

Original languageEnglish
Title of host publicationProceedings of the ASME Pressure Vessels and Piping Conference 2009
Number of pages11
StatePublished - 2010
Externally publishedYes
Event2009 ASME Pressure Vessels and Piping Conference, PVP 2009 - Prague, Czech Republic
Duration: 26 Jul 200930 Jul 2009

Publication series

NameAmerican Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP
ISSN (Print)0277-027X


Conference2009 ASME Pressure Vessels and Piping Conference, PVP 2009
Country/TerritoryCzech Republic


Dive into the research topics of 'Analysis of constant and variable amplitude strain-life data using a novel probabilistic Weibull regression model'. Together they form a unique fingerprint.

Cite this