"Validation of the Two-Parameter-Fracture Criterion for Various Crack C" by Mounia Malki
 

Theses and Dissertations

Author

Mounia Malki

Issuing Body

Mississippi State University

Advisor

Newman, James C., Jr.

Committee Member

Sullivan, Rani Warsi

Committee Member

Lacy, Thomas E.

Date of Degree

5-4-2018

Original embargo terms

MSU Only Indefinitely

Document Type

Graduate Thesis - Campus Access Only

Major

Aerospace Engineering

Degree Name

Master of Science

College

James Worth Bagley College of Engineering

Department

Department of Aerospace Engineering

Abstract

The Two-Parameter-Fracture-Criterion (TPFC) was validated using an elastic-plastic two-dimensional (2D) finite-element code, ZIP2D, with the plane-strain-core concept. Fracture simulations were performed on three crack configurations: (1) middle-crack-tension, M(T), (2) single-edge-crack-tension, SE(T), and (3) single-edge crack-bend, SE(B), specimens. They were made of 2014-T6 (TL) aluminum alloy. Fracture test data from Thomas Orange work (NASA) were only available on M(T) specimens (one-half width, w = 1.5 to 6 in.) and they were all tested at cryogenic (-320oF) temperature. All crack configurations were analysed over a very wide range of widths (w = 0.75 to 24 in.) and crack-length-to-width ratios ranged from 0.2 to 0.8. The TPFC was shown to fit the simulated fracture data fairly well (within 6.5%) for all crack configurations for net-section stresses less than the material proportional limit. For M(T) specimens, a simple approximation was shown to work well for net-section stresses greater than the proportional limit. Further study is needed for net-section stresses greater than the proportional limit for the SE(T) and SE(B) specimens.

URI

https://hdl.handle.net/11668/16606

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