- SOW.pdf

SOW:

Fixed Base Modal Correction

GRC needs a method for extracting fixed base modes while a structure is mounted on a shake table. ATA has developed a method for extracting fixed base modes from a test article on a shaker table. The key to the method is to use resultant accelerations of the table (such as rigid body accelerations) as references when calculating frequency response functions (FRFs). When this is done, the modes extracted from the resulting FRFs correspond to fixed base modes. The modal survey will be a test on the flight hardware of the Sierra Space Dream Chaser Space Plane. The contractor shall provide off-site and on-site support to help NASA Glenn with extracting modal parameters of the Dream Chaser. The support will involve performing pretest analysis and converting pretest analysis results into a suitable format for use. On-site support will also be required during the actual Dream Chaser vibration test campaign.