Theses and Dissertations


Sullivan, Rani W.

Committee Member

Belk, Davy M.

Committee Member

Hammi, Youssef

Date of Degree


Original embargo terms

Embargo 1 year

Document Type

Graduate Thesis - Open Access


Aerospace Engineering

Degree Name

Master of Science (M.S.)


James Worth Bagley College of Engineering


Department of Aerospace Engineering


Lightweight sandwich composite structures exhibit high strength and bending stiffness and have been used in various load-bearing aerospace structures. A primary weakness of these structures is the low interfacial strength that can result in the disbonding between the facesheet and the core. Through-thickness reinforcement techniques, such as stitching, can be utilized to improve the interfacial strength of sandwich composites. This study focuses on fabrication and structural testing of stitched sandwich composite main landing gear (MLG) strut doors. The MLG strut doors are constructed from carbon fiber non-crimp fabric facesheets and closed-cell foam core that are stitched using a modified lock stitching technique. To assess the effects of stitching, two doors were fabricated, one with and one without through-the-foam stitching. A vacuum-assisted resin transfer molding process was used to infuse the doors. The strut doors were subjected to quasi-static loading, and the mechanical responses of the stitched and unstitched strut doors are presented.

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