Graduation Semester and Year
Fall 2025
Language
English
Document Type
Dissertation
Degree Name
Doctor of Philosophy in Aerospace Engineering
Department
Mechanical and Aerospace Engineering
First Advisor
Andrew Makeev
Second Advisor
Guillaume Seon
Abstract
Adhesively bonded Polymer Matrix Composites (PMCs) offer significant potential for weight reduction and manufacturing efficiency in aerospace structures by reducing reliance on mechanical fasteners. However, their structural performance is highly sensitive to manufacturing defects such as bondline porosity, initial disbonds, and thickness variations. Moreover, the complex and interacting failure mechanisms governing bonded-joint behavior under static and fatigue loading make reliable strength prediction challenging, increasing the risk of unexpected loss of structural integrity and ultimately limiting the widespread adoption of bonded PMC structures. High-fidelity numerical models capable of capturing all relevant bondline failure modes and representing the effect of defects are therefore essential to support qualification and improve defect-tolerance assessment. Yet, most existing models struggle to simultaneously capture the failure mechanisms present in real bonded joints and the complex material response of structural adhesives used in PMC applications, and they typically do not provide a unified framework for both static and fatigue analysis.
This dissertation uses a recently-developed continuous–discontinuous framework capable of predicting arbitrary, solution-dependent crack paths in defective adhesive bondlines under static loading. The framework couples an elasto-plastic constitutive model with isotropic continuum damage and an enriched finite element formulation to represent diffuse microcracking, damage localization, and discrete crack propagation within a single numerical description. However, its application has so far been limited to static conditions as standard XFEM implementations do not allow control over damage evolution and assume brittle behavior in fatigue.
To address these limitations and extend the framework to high-cycle fatigue, this work introduces nonlocal enhancements and a cohesive-segment-based fatigue damage strategy that enables cycle-dependent crack initiation and progressive degradation in quasi-brittle adhesives. The methodology is demonstrated using two-dimensional finite element models of double-cantilever beam specimens with representative defects and is validated against experimental data in the static regime, establishing a unified platform for simulating both static and fatigue-driven fracture in adhesive bondlines.
Keywords
Polymeric Matrix Composites, Adhesive Modeling, Fatigue Analysis, Crack Propagation, XFEM
License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
Sponton, Louis Pierre, "DEVELOPMENT OF A MODEL FOR PREDICTION OF BONDLINE FAILURE IN POLYMER MATRIX COMPOSITES (PMCS) USING ABAQUS AND THE EXTENDED FINITE ELEMENT METHOD" (2025). Mechanical and Aerospace Engineering Dissertations. 440.
https://mavmatrix.uta.edu/mechaerospace_dissertations/440