Structural health monitoring methods for flight safety

Researchers demonstrated three complementary methodologies in Structural Health Monitoring (SHM) for aircraft and spacecraft materials and structures. First, the quality of manual riveting processes was examined. Quality assurance indicators were developed based on the loads acting across the rivet gun-part interface to identify riveting processes with skewed delivery, circular indentations, and bucking bar slip to define susceptibility to future damage in fuselage structures. Second, using a semi-realistic combined thermo-acoustic testing apparatus, it was demonstrated that certain types of local damage in mechanically attached thermal barriers in spacecraft are less apparent offline than online when operating temperatures are acting. Third, beamforming methods for steering elastic waveforms and processing phased sensor array data were used to identify low-level incipient damage in large friction stir welded metal tank structures.