Abstract
This dissertation explores the use of composite materials in enhancing coastal protection systems, focusing on the structural performance of SEAHIVE® units. Through experimental testing and finite element modeling, the research examines three key areas: internal GFRP bar reinforcement, external GFRP wrap reinforcement, and the compressive behavior of GFRP bars. Each study adopts a unique methodological approach to address specific challenges in the design and performance of SEAHIVE® units. The first study evaluates the performance of SEAHIVE® units reinforced with internal glass fiber-reinforced polymer (GFRP) bars. These hexagonal, hollow, and perforated units were tested under transverse compression, longitudinal compression, and four-point bending to understand their behavior under various loading conditions. The experimental setup included strain gauges, linear variable differential transformers (LVDTs), and digital image correlation (DIC) techniques to capture detailed strain, displacement, and crack propagation data. The results revealed that initial cracks typically form at stress concentration points, such as the perforations, and propagate through the structure, leading to failure. Finite element modeling (FEM) in ABAQUS was employed to simulate these tests, providing insights into stress distributions, crack patterns, and the influence of geometrical and material properties. Key findings showed that internal GFRP reinforcement primarily holds the concrete together post-failure, emphasizing the need for optimized reinforcement detailing to improve load-bearing capacity.