Aproximation of fatigue curve and fatigue limit of fibre composite using random Daniels’ sequence and Markov chains

Abstract

The possibility of using a model based on random Daniels’ sequence and Markov chain theory for approximation of S-N fatigue curve of fiber reinforced material is studied. The model allows observing the connection between static strength distribution parameters and parameter of S-N fatigue curve. Although the model is too simple and does not provide numerical correspondence with experimental fatigue test data, it can explain the existence of a fatigue limit and can be used as a nonlinear regression model of S-N fatigue curve when taking into account the existence of a random fatigue limit. By using of this model fatigue curve (and especially, fatigue limit) changes as a consequence of tensile strength parameter changes may be predicted. A numerical example of carbon-fiber fatigue test dataset processing is provided.

Keywords

• fibers
• strength
• fatigue
• Daniels’ sequence
• Markov chains