A continuing investigation into the stress field around two parallet-edge cracks in a finite body

by Gilman, Justin Patrick

Abstract (Summary)
The goal of this research was to extend the investigation into a method to

represent and analyze the stress field around two parallel edge cracks in a finite body.

The Westergaard-Schwarz method combined with the local collocation method was used

to analyze different cases of two parallel edge cracks in a finite body. Using this method

a determination of when two parallel edge cracks could be analyzed as isolated single

edge cracks was determined

Numerical experimentation was conducted using ABAQUS. It was used to obtain

the coordinate and stress information required in the local collocation method. The

numerical models were created by maintaining one crack at a fixed length while varying

the length of the second crack as well as the separation distance of the two cracks. The

results obtained through the local collocation method were compared with the finite

element obtained J-Integrals to verify the accuracy of the results.

The results obtained in the analysis showed that the major factor in determining

when the second crack?s stress field has to be considered was the crack separation

distance. It was found that a reduction in the second crack?s length did not have a

significant effect on overall stress intensity factors of the fixed crack. A larger change in

the opening mode stress intensity factor can be seen by varying the crack separation

distance. As well as seeing a steady reduction in shear mode stress intensity factors as the

crack separation was increased. The results showed that after a certain crack separation

distance the two cracks could be analyzed separately without introducing significant

error into the stress field calculations.

Bibliographical Information:

Advisor:Hogan, Harry; Chona, Ravinder; Fry, Gary; Reddy, J. N.

School:Texas A&M University

School Location:USA - Texas

Source Type:Master's Thesis

Keywords:stress intensity factors j integrals parallel cracks


Date of Publication:12/01/2004

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