Date of Award

5-21-2004

Degree Type

Thesis

Degree Name

M.S.

Degree Program

Engineering

Department

Mechanical Engineering

Major Professor

Verges, Melody

Second Advisor

Guillot, Martin

Third Advisor

Herrington, Paul

Fourth Advisor

Schilling, Paul

Abstract

This work is aimed at investigating out-of-plane displacement data on the top surface of a loaded composite laminate containing microcracking damage to explore the feasibility of using surface data to locate microcracks in laminates. In this study, finite element models are created for eleven different cross-ply IM7/977-2 laminates with ply numbers varying from four to ten. Here, each ply thickness is 0.127mm, which is the common laminate thickness commercially available for this material system. For each model a range of transverse loadings are applied and the surface displacement data are analyzed along the mid-plane perpendicular to the plane of the crack. The following outof- plane surface data parameters are obtained for each case: the minimal value above the crack tip, the peak value, and the far-field value. The difference in the peak and minimal values for a given loading is important in determining whether or not the optical technique is sensitive enough to resolve the data. The lateral distance to the peak values and the far-field values are also obtained. These distances are important in determining whether or not an optical system can spatially resolve the data. Results suggest that an optical technique such as digital holography could resolve, at a minimum, the data of [0/90/90/0], [0/90/90/90/90/0], and [0/0/90/90/90/90/0/0] laminates subjected to transverse loads of 1000 MPa.

Rights

The University of New Orleans and its agents retain the non-exclusive license to archive and make accessible this dissertation or thesis in whole or in part in all forms of media, now or hereafter known. The author retains all other ownership rights to the copyright of the thesis or dissertation.

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