Damage Characterization and Remaining Life Assessment of Structural Components with Nonlinear Vibro-Acoustic Technique

This project deals with development of Nonlinear Vibro-Modulation (NVM) technique capable of detection, location and characterization of material defects and damage at macro, meso and micro scale levels and prediction of remaining life of the material. Theproposed approach utilizes physical phenomena associated with nonlinear interaction at the defect interface, which manifest itself though appearance of additional spectral components at intermodulation frequencies. Localized nonlinear behavior of theinterface causes modulation of passing high frequency ultrasonic wave by low frequency vibrations drawing direct relationship between severity of damage and magnitude of nonlinear parameters or modulation intensity. Analysis of the data obtained throughnonlinear vibro-modulation experiments and destructive techniques (i.e. optic and electronic microscopy) will result in establishing criteria for the damage evaluation model, which will be developed in Phase II of proposed project. Availability of suchwill allow for synchronization and correlation of the parameters obtained though nonlinear measurements with those, traditionally associated with fracture (flaw size, density and cycles to failure), facilitating predicting of material further performanceand remaining life. The developed technology will greatly benefit to the broad range of industries with aging industrial infrastructure including the energy (utilities), chemical/petrochemical, military and civilian aerospace, construction, automotive,shipbuilding, rail, ordnance and electronics sectors by increasing infrastructure's reliability, safety, and useful life.