Session: 01-08-03: Nondestructive Evaluation and Structural Health Monitoring 3

Paper Number: 162455

162455 - Detection and Healing of Delamination Damage in 2d Cfrp Structures Using Piezoelectric-Actuated Lamb Waves Under Applied Loading 

Delamination is a common form of damage in CFRP composite structures resulting from fatigue loading. Due to delamination occurring beneath the surface of FRP laminates, they can be difficult to detect. Catastrophic structural failure can ensue if delamination damage is left undetected. In this work, a technique based on piezoelectric macro-fiber composite (MFC) actuators and sensors is used to detect and then heal delaminations. The same configuration of MFCs is used for both purposes. Both glass fiber and carbon fiber reinforced composites are tested using the present method. A 2D composite panel  structure with an elliptic hole cut-out  is employed, which represents realistic structure to which the technique may be applied. An embedded delamination is created near the hole using Teflon inserts, so that the extent of damage before and after healing can be accurately measured. During damage detection, signals at the MFC sensors are recorded for both delaminated and baseline specimens. Comparison with baseline signals provides a damage index based on the normalized correlation moment (NCM). Healing is performed in the presence of applied tensile load on the laminate of around 7% UTS.   Damage index values are found to reduce after the healing phase, indicating successful delamination healing. A finite element model of damage detection is also constructed based on experimental data and it shows comparable NCM damage index values as the experiment.

Presenting Author: Samit Roy University of Alabama

Presenting Author Biography: Dr. Samit Roy received his Ph.D. in Engineering Science & Mechanics from Virginia Tech in Blacksburg, Virginia. He is currently the William D. Jordan Endowed Professor in the Department of Aerospace Engineering and Mechanics at University of Alabama (UA). Dr. Roy's research interest is directed towards multi-scale modeling and life-prediction of fiber reinforced polymer composites and structural adhesives subjected to aggressive environmental conditions. He is also actively involved in the application of nanostructured reinforcements in enhancing performance of composite materials. He has developed structural health management concepts that include sensor placement optimization for structural weight and cost reduction, as well as smart materials for non-autonomous self-healing. He has authored over 200 peer-reviewed journal articles and book chapters. He was elected Associate Fellow of the American Institute of Aeronautics and Astronautics (AIAA) in 2004, elected Fellow of ASME in 2010, and Fellow of American Society for Composites (ASC) in 2022. He was elected Chairman of the ASME NanoEngineering for Energy and Sustainability (NEES) steering committee in 2014, and Division Chair, Emerging Composite Technologies Technical Division, of the American Society for Composites in 2022. He is the recipient of the ASC Outstanding Researcher Award in Composites in 2019 and again in 2023.