Impact damage assessment in carbon fiber reinforced composite using vibration-based new damage index and ultrasonic C-scanning method

Abstract

This paper presents a combination of the Vibration-based method and Non-destructive Ultrasonic C-scan method to identify, locate, and quantify the damage in impacted carbon composite fiber reinforced structure. The main objective of work consists of developing a new method to assessment of damage in carbon composite by using a different method to be applied to structural health monitoring. Experiments were carried out on laboratory specimens, which consists of carbon/epoxy laminates having three different stacking sequences ([0/0]s, [0/90]s, and [45/0–45/90]s) subjected to three different impact energies (7 J, 14 J, and 24 J) using conical shape impactor. Frequency Response Function (FRF) for intact and damaged specimens was obtained by using hammer and accelerometer sensors. FRFs are analysed using suitable metrics, including a new one, which is compared in terms of their capability for damage identification. Afterword, the ultrasonic C-scanning method is used to locate and quantify the damage in the specimen. The ultrasonic C-scanning works on the principle of ultrasonic reflection at the interface of impedance mismatch. In this method defects are based on the amplitude of ultrasonic high-speed waves; a qualitative approach is used to identifying the defects while measuring the amplitude of the signals. This technique has demonstrated great potential for damage localization and extension in carbon composites. Finally, the new method is proposed to identify and localization of damage in the impacted specimen using the Vibration-based method and Ultrasonic C-scanning methods.