The Use of Vibrothermography for Detecting and Sizing low Energy Impact Damage of Cfrp Laminate

Abstract

The detection and evaluation of low energy impact damage of carbon fibre reinforced polymer (CFRP) laminate were investigated using vibrothermography. To this goal, four specimens were begun with low energy impact with different energies, followed by the detection using vibrothermography. The detection results show that the matrix crack is mainly located closer to the surface opposite to impact, while the delamination is mainly closer to the impact surface. Then, an iterative algorithm based on maximal entropy theory was proposed for thermal image segmentation and on this basis, the damaged area was determined. The obtained results show the damaged area increases with the increase of impact energy and the damaged area and impact energy may present an approximate linear relationship.

Modal-based vibrothermography using feature extraction with application to composite materials

“…However, in research activities that involve vibrothermography, the importance of modal parameters and strain distributions has often been overlooked. [19][20][21][22] These omissions almost always result in poor or incorrect choices of excitation frequency and location which are unable to excite the (correct) resonance of the inspected object effectively, so that a high amplitude for the excitation force has to be used to generate sufficient strain to reveal local damage sites.…”

Resistance behaviour of carbon fibre-reinforced polymers subjected to lightning strikes: Experimental investigation and application

“…Carbon fibre-reinforced polymers (CFRPs) are widely used in renewable energy, aviation, aerospace and other fields because of their light weight, high strength and high stiffness. 1,2 Lightning is a typical natural plasma phenomenon that causes inexorable damage to almost all directly struck materials. CFRPs used in wind turbines and aircraft are inevitably subjected to lightning threats.…”