Fatigue Life Calculation with Loads Varying in Magnitude and Direction NAVAIR Lakehurst

Format:

Conference/Event

Author/Creator:

Altobelli, Altobelli, author.

Contributor:

Chandrupatla, Tirupathi R.

Conference Name:

SAE 2013 World Congress & Exhibition (2013-04-16 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2013

Summary:

In fatigue life prediction, it is common to analyze a componentsubjected to a load-versus-time history that varies in magnitudeover time. In established methods, it is assumed that thedirections of the applied loads do not change, so stresses alongthe same reference plane can be compared as unidimensionalquantities. Put differently, these methods require that theprincipal stress orientation remains the same throughout the loadhistory.This work aims to determine the fatigue life of a componentexperiencing a load-versus-time history that produces stressesvarying in both magnitude and principal stress orientation. Toaccomplish this, all six components of the stress tensor arerequired throughout the loading history. By choosing a cut planedefined by the normal direction n, the normal stresses can bedetermined. The application of the rainflow counting method canthen be used to convert the normal stresses into equivalent fatiguecycles. The Goodman method can compare these cycles against an S-Nor Wohler curve, while Miner's rule calculates the life Lcorresponding to the plane n.It is necessary to find the cut plane that minimizes L whileensuring that n remains a unit normal. The search for min L iscompleted using the Nelder and Mead optimization. The methodpresented in this paper can evaluate the minimum life and the planeon which a crack will initiate

Notes:

Vendor supplied data

Publisher Number:

2013-01-0999

Access Restriction:

Restricted for use by site license