Session: 05-11-01: Multifunctional Composites and Structures: Mechanics, Modeling, and Space Applications

Paper Number: 149569

149569 - Delamination Propagation in Cfrps: From In-Situ Discoveries to Ex-Situ Applications 

This research will examine ex-situ delamination propagation in Carbon Fiber Reinforced Polymers (CFRPs), building on previous discoveries made through in-situ experiments using Digital Image Correlation (DIC) techniques. In the early stages, this investigation is concerned with surface strain mapping during Compression After Impact (CAI) tests aimed to identify the onset and progression of delamination. A technologically innovative speckle pattern and advanced imaging technique are utilized to propose a new non-destructive evaluation (NDE) method. Its application allows for accurate monitoring and analysis of barely visible impact damage (BVID) on composites which is vital for maintaining aerospace components’ structural integrity.

The research shows that this NDE technique has a higher sensitivity which can detect delaminations earlier hence improving the accuracy of damage assessment in CFRPs significantly. The behavior of composite materials under loads has been studied by conducting in-situ experiments which provide some insight into critical thresholds as well as strain patterns that occur before delamination occurs. These findings are then transferred to ex-situ conditions thereby providing an alternative way to look at composite damage assessment that can be used in practical maintenance settings.

The adaptation from in-situ to ex-situ involves a comprehensive analysis of the strain patterns and their correlation with delamination propagation. The study employs high-resolution imaging and precise measurement tools to capture the minute details of strain distribution and its effects on the composite structure. The ex-situ method developed from these findings offers a robust framework for early damage detection, enabling more effective and timely maintenance of aerospace structures.

The significance of this research lies in its potential to transform the current practices of NDE in aerospace engineering. Traditional methods often fail to detect BVID until it has progressed to a more critical stage, compromising the safety and reliability of the structure. The proposed NDE method, grounded in in-situ discoveries, addresses this gap by providing a more accurate and sensitive means of detecting early-stage delamination.

Furthermore, this study highlights the importance of integrating advanced DIC techniques with practical NDE applications. The transition from in-situ to ex-situ not only validates the experimental findings but also demonstrates the feasibility of implementing these techniques in real-world scenarios. The implications of this research extend beyond aerospace engineering.

The study's conclusions point to significant advancements in the early identification of damage in CFRPs, which will enhance the general safety and integrity of aerospace structures. This research opens the door for more dependable and effective maintenance procedures, which will ultimately improve the lifespan and performance of composite materials in crucial applications by developing NDE techniques through the adaptation of in-situ discoveries to ex-situ applications.

Presenting Author: Kais Jribi Florida Polytechnic University

Presenting Author Biography: Kais Jribi is an assistant professor in mechanical engineering at Florida Polytechnic University. He completed his Ph.D. in Aerospace Engineering with a focus on Structures & Materials at Embry-Riddle Aeronautical University in May 2024. His research interests include composite materials, structural dynamics, and aerospace structures. Kais has professional experience in CFRP manufacturing, mechanical testing, finite element modeling, and digital image correlation.

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