Control of the through-thickness temperature distribution in carbon composite aerospace parts during induction welding

Abstract

The increasing content of thermoplastic composites in the aerospace industry requires the application of new joining technologies. Their main assembly advantage is rivetless joining, which needs to be examined in greater detail in order to compensate the higher costs of these materials. Induction welding is already used in aerospace industry and shows a high potential for the application in helicopter manufacturing. In order to implement this technology in serial production, the main requirement is to determine and control the process temperature distribution. A wide range of literature describing various approaches that characterize the aforementioned temperature distribution exists. Although all approaches validate their findings by temperature measurement on the surfaces of their parts, their results seem inconsistent due to different results. In this article, a new approach is presented and validated by interlaminar temperature measurement. Based on this new approach, for induction welding, effects that are not yet described are discussed. Hereby, cooling of the surface by air jets is investigated as a mean to influence the thermal effects of the induction welding process.