Theses and Dissertations
Issuing Body
Mississippi State University
Advisor
Newman, James C., Jr.
Committee Member
Lacy, Thomas E.
Committee Member
Sullivan, Rani Warsi
Date of Degree
12-8-2017
Document Type
Graduate Thesis - Open Access
Major
Aerospace Engineering
Degree Name
Master of Science
College
James Worth Bagley College of Engineering
Department
Department of Aerospace Engineering
Abstract
A two-parameter fracture criterion (TPFC) is used to correlate and predict failure loads on cracked configurations made of ductile materials. The current study was conducted to validate the use of the fracture criterion on more brittle materials, using elastic-plastic finite-element analyses with the critical crack-tip-opening angle (CTOA) failure criterion. Forman generated fracture data on middle-crack tension, M(T), specimens made of thin-sheet 7075-T6 aluminum alloy, which is a quasi-brittle material. The fracture data included a wide range of specimen widths (2w) ranging from 3 to 24 inches. A two-dimensional (2D) finite-element analysis code (ZIP2D) with a ''plane-strain core" option was used to model the fracture process. Fracture simulations were conducted on M(T), single-edge-crack tension, SE(T), and single-edge-crack bend, SE(B), specimens. The results supported the TPFC equation for net-section stresses less than the material proportional limit. However, some discrepancies were observed among the numerical results of the three specimen types. Thus, more research is needed to improve the transferability of the TPFC from the M(T) specimen to both the SE(T) and SE(B) specimens.
URI
https://hdl.handle.net/11668/19494
Recommended Citation
Ouidadi, Hasnaa, "Validation of the Two-Parameter Fracture Criterion Using Critical CTOA on 7075-T6 Aluminum Alloy" (2017). Theses and Dissertations. 4940.
https://scholarsjunction.msstate.edu/td/4940