Specimen geometry and material property uncertainity model for probabilistic fatigue life predictions
Loading...
Date
2006-08
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand)
Abstract
The analysis of cracks within structure is an important application if the damage tolerance and durability of structures and components are to be predicted. As part of the engineering design process, engineers have to assess not only how well the design satisfies the performance requirements but also how durable the product will be over its life cycle. Often cracks cannot be avoided in structures; however the fatigue life of the structure depends on the location and size of these cracks. In order to predict the fatigue life for any component, crack growth study needs to be performed. Fatigue life is related to and is affected to a great extent with the uncertainties in both the material properties and the specimen or component geometrical parameters. The intent of the work is to contribute to the fundamental understanding of fatigue life and its relation with these uncertainties. Fatigue life data exhibits wide scattered results due to inherent microstructural inhomogeneity in the material properties even if the test specimens are taken from the same lot and tested under same loading condition. As the fatigue testing is time consuming and costly, setting up of an analytical method for prediction of fatigue life is necessary. In the present work an approximate analytical model derived from the energy theorem and probabilistic nature of material properties and specimen geometry parameters are combined and correlated to determine the associated error in the predicted fatigue life. The prediction is based on minimization of error. The predicted values of fatigue life are compared with the experimental values available in literature.
Description
Keywords
null