Panoramic modal holographic interferometry

This thesis describes a new approach to modal analysis in which time-average holograms are recorded through a dual Panoramic Annular Lens (PAL) optical system. When inserted into a cylindrical structure, a relatively large portion of the 360° region surrounding the system is observed. The dual PAL approach is used to study the modal response of an aluminum ring. Quantitative results agree well with those obtained using standard impact hammer testing and standard single perspective holographic methods; qualitative comparisons are made between panoramic hoio-interferograms and those recorded using standard time-average holographic recording techniques. In addition, the dual PAL system is utilized to acquire 36 modal holo-interferograms of a Space Shuttle Main Engine (SSME) Turbine Inlet Bellows Liner (TIBL). The main advantages of dual PAL based time-average panoramic holo-interferometry are that spatial definition is optimized and that displacements are recorded with nearly constant sensitivity over the entire field of view.