In recent years, the observation of the behaviour of components during the production process and over their life cycle is of increasing importance. Structural health monitoring, for example of carbon composites, is state-of-the-art research. The usage of Fibre Bragg Gratings (FBGs) in this field is of major advantage. Another possible area of application is in foundries. The internal state of melts during the solidification process is of particular interest. By using embedded FBGs, temperature and stress can be monitored during the process. In this work, FBGs were embedded in aluminium alloys in order to observe the occurring strain. Two different FBG positions were chosen in the mould in order to compare its dependence. It was shown that FBGs can withstand the solidification process, although a compression in the range of one percent was measured, which is in agreement with the literature value. Furthermore, different lengths of the gratings were applied, and it was shown that shorter gratings result in more accurate measurements. The obtained results prove that FBGs are applicable as sensors for temperatures up to 740 °C.

ZusammenfassungIn diesem Beitrag wird ein neuartiger Ansatz zur Schadensdetektion in Stromversorgungskabeln vorgestellt. Die Funktionalität des Messsystems kann bezüglich des durch Makrobiegungen induzierten Anstiegs des Dämpfungsbelags verifiziert werden. Durch den verwendeten Integrationsansatz sind Mantelschäden im Stromversorgungskabel detektierbar, wodurch langfristige Ausfallgründe frühzeitig erkannt werden. Über eine integrierte optische Faser und ein optisches Zeitbereichsreflektometer kann unabhängig von der elektrischen Energieübertragung im Kabel eine exakte und effiziente Schadenslokalisierung sichergestellt werden, was wiederum eine Zeit- und Kostenersparnis zur Folge hat.