Evaluating impact damage in kevlar/carbon composites by using laser vibrometry and active infrared thermography

Abstract

Recent developments in electronics have demonstrated some advantages of using carbon fibres in manufacturing flexible PCBs thus requiring to elaborate some new approaches for checking PCB quality. Barely visible impact damage (BVID) represents a typical type of defects in carbon-based composites. In this study, the two inspection techniques, namely active infrared thermography and laser vibrometry, were comparatively used for detecting BVID in composite materials manufactured by three-dimensional printing from kevlar and carbon fibres. The comparative analysis of the composite resistance towards multifold impacting with the total energy of up to 15 J has demonstrated advantages of the hybrid configuration obtained by using the technology of additive manufacturing. The measurement of damping characteristics of the composites in the 50-100 kHz frequency range has also confirmed the ability of the hybrid composite to absorb more energy than classical single component materials.