Kinematics of Inter-Ply Interfaces In Composite Manufacturing

<p>The ubiquitous usage of polymer matrix composites in many applications demands a comprehensive understanding of composite interfaces and processing induced residual stresses, which critically affect both the manufacturing processes and the deformation mechanisms. Processing induced residual stresses are often responsible for causing warping, delamination, and dimensional instability in composite structures. This research includes new in-situ experimental approaches, cure cycle design, interface modification, and thermomechanical modeling for developing a fundamental understanding of the cure kinetics during composite manufacturing. Strains, ply-movement, and formation of defects are observed in-situ using digital image correlation (DIC) during the autoclave cure cycle for the first time. The processing-induced defects in the composite are further characterized by X-ray micro-computed tomography (micro-CT). A non-destructive method is developed to calculate residual stresses using DIC Strains in combination with temperature-dependent moduli obtained from Dynamic Mechanical Analysis (DMA) and Classical Laminate Theory (CLT). Cure cycle design with interrupted cure and interface modification with ZnO nanorods experiments are developed to reduce these processing- induced residual stresses and thereby increase laminate strength. The experimental results are validated through thermomechanical modeling of the composite cure process.</p>

Name thesis:degree_name

Doctor of Philosophy in Aerospace Engineering

Level thesis:degree_level

Dissertation - Open Access

Discipline thesis:degree_discipline

Aerospace Engineering

Year

2021

Author dc:creator

• Chava, Sandeep

• Carbon Fiber Composites
• Digital Image Correlation
• Autoclave Processing
• Residual Stresses
• Reaction Kinetics
• Composite Process Modeling
• Structures and Materials

Repository record dc:identifier

https://commons.erau.edu/edt/635

OAI identifier oai:identifier

oai:commons.erau.edu:edt-1651