Smart supporting structures in space applications

In this paper, we present an application devoted to measure the dynamic response of a prototype of a support of a star tracker. Four different techniques have been used and compared with each other. Specifically Electronic Speckle Pattern Interferometry and Speckle Shearography have been used as full field modal appropriation techniques, impact hammer and accelerometer as a broad band conventional technique and finally broad band with impact hammer and FBG sensor as a newly proposed methodology. Modal parameters have been retrieved using all the four methodologies described above and compared. We have demonstrated that FBG sensors can be used to retrieve modal parameters useful as indicators of the state of health of a structural component. When embedded the FBG can be used actively also during the qualification process of the smart component as well as in service for shape monitoring. This latter purpose is important for precision pointing instruments such as the star tracker under investigation.