Composites are being increasingly used to replace metals, in several industries because of their light weight, corrosion resistance, and mechanical strength. The integrity of adhesively bonded structures is crucial for ensuring their performance and strength, which can be compromised in the presence of disbonds. Hence there is need for a robust and effective Non Destructive Evaluation (NDE) technique to detect potential defects in such structures. Microwave NDE is well suited for lossless and low loss composite materials which allow electromagnetic waves to propagate and interact with them. In this paper, we investigate far field measurements with pulsed excitation for detecting disbonds in metal-composite joints. The far field measurements are processed using time reversal methods to detect and image the disbonds. Simulation studies and parametric analysis demonstrate the feasibility of the technique, and is validated by far field experimental results using a pulsed time domain laboratory setup. Time reversed images show accurate detection of single and multiple disbonds in the composite structures. Preliminary testing is being done in microwave frequencies (2-18 GHz), but the system can be easily scaled to millimetre or terahertz wave frequencies for increased resolution. © 2016, The Composites and Advanced Materials Expo (CAMX). All rights reserved.
Far field microwave time reversal imaging for NDE of composites
Tamburrino, A.Writing – Review & Editing
2016-01-01
Abstract
Composites are being increasingly used to replace metals, in several industries because of their light weight, corrosion resistance, and mechanical strength. The integrity of adhesively bonded structures is crucial for ensuring their performance and strength, which can be compromised in the presence of disbonds. Hence there is need for a robust and effective Non Destructive Evaluation (NDE) technique to detect potential defects in such structures. Microwave NDE is well suited for lossless and low loss composite materials which allow electromagnetic waves to propagate and interact with them. In this paper, we investigate far field measurements with pulsed excitation for detecting disbonds in metal-composite joints. The far field measurements are processed using time reversal methods to detect and image the disbonds. Simulation studies and parametric analysis demonstrate the feasibility of the technique, and is validated by far field experimental results using a pulsed time domain laboratory setup. Time reversed images show accurate detection of single and multiple disbonds in the composite structures. Preliminary testing is being done in microwave frequencies (2-18 GHz), but the system can be easily scaled to millimetre or terahertz wave frequencies for increased resolution. © 2016, The Composites and Advanced Materials Expo (CAMX). All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
