Theses and Dissertations

Issuing Body

Mississippi State University

Advisor

Newman Jr., James C.

Committee Member

Sullivan, Rani Warsi

Committee Member

Lacy Jr., Thomas

Date of Degree

5-12-2012

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

Many aircraft are designed using the Damage-Tolerance concept. This concept assumes that a structural component is flawed during the manufacturing process. A central feature in this concept is the fatigue-crack-growth-rate properties of the material used in its construction. ASTM E-647 standard describes how fatigue crack growth tests are to be conducted. In the late 1960’s, Wolf Elber discovered the concept of crack closure. He showed that the crack would close prematurely even while under tensile loading. A central feature in this concept is called the crack opening load. The method in ASTM E-647 used to calculate the crack opening load has been found to be inadequate for high load ratios R (Pmin/Pmax>0.4) tests. Herein, an algorithm implementing the least squares method was developed to determine the crack-opening load for low and high R tests on a variety of materials for fatigue crack growth tests conducted on compact C(T) specimens.

URI

https://hdl.handle.net/11668/17979

Comments

ASTM||Load||Opening||Crack||Fatigue

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