Date Approved
8-4-2026
Embargo Period
8-4-2027
Document Type
Dissertation
Degree Name
Ph.D.
Department
Mechanical Engineering
College
Henry M. Rowan College of Engineering
Advisor
Behrad Koohbor, Ph.D.
Committee Member 1
Francis M. Haas, Ph.D.
Committee Member 2
Paromita Nath, Ph.D.
Committee Member 3
James A. Newell, Ph.D.
Committee Member 4
Paul R. Chiarot, Ph.D.
Keywords
Debonding;Digital Image Correlation;Transverse Cracking;Unidirectional Composites
Disciplines
Engineering | Mechanical Engineering
Abstract
Transverse cracking in composites is a critical damage mechanism that initiates at the fiber-matrix interface and propagates through the matrix to form ply-thick cracks. The initiation and progression of this damage is inherently multiscale and therefore challenging to investigate experimentally. This work utilizes experimental protocols for characterizing and quantifying fiber-matrix interfacial debonding, with an emphasis on the mechanisms that drive damage evolution and stiffness degradation under cyclic loading. Leveraging macro-fiber-based approaches, composite representative volume elements (RVEs) are fabricated by embedding glass macro fibers (1 mm dia) in an epoxy matrix. The specimens are subjected to both monotonic and cyclic loading, while failure mechanisms are examined using full-field optical digital image correlation (DIC). A key outcome of this study is the ability to quantify the number of debonded fibers as a function of strain and cycle number. The correlations between microscale damage and macroscale performance reveal the underlying mechanisms linking interfacial debonding to stiffness reduction and provide experimental evidence supporting percolation-type transverse crack formation in unidirectional composites. Furthermore, cyclic loading kinematics and kinetics of the fiber debonding process differ between peak and minimum stresses within each cycle. Overall, the proposed framework offers a robust experimental pathway for linking microscale damage evolution to macroscale mechanical response in composite materials.
Recommended Citation
Hazaveh, Zaynab, "Multiscale Characterization of Fiber-Matrix Interface Mechanics and Failure in Fiber Reinforced Composites" (2026). Theses and Dissertations. 3569.
https://rdw.rowan.edu/etd/3569
