A Miniaturized Active Thermography System to Inspect Composite Laminates

Abstract

With the rapid increase of the integration and complexity of industrial components, the inaccessibility and inapplicability of existing nondestructive testing devices have become a bottleneck for in situ inspection of these objects. This article introduces a miniaturized active thermography system featured with a small-size, low-resolution, and low-cost thermal sensor, where two optional excitation sources including flash and laser are integrated. Dedicated data analysis approaches to evaluate defects are proposed considering the degraded signal quality. Three carbon fiber-reinforced polymer laminates with a variety of defects are evaluated quantitatively and qualitatively using the proposed system by comparing with two existing nonminiaturized inspection systems. The results show that the proposed system can work effectively for the degradation assessment of composite laminates. Even with the technical limitations that affect the detectability, for instance, the low pixel resolution, this technique will play an important role to inspect components featured with geometrically intricate space.