Classification of Damage Signatures in Composite Plates using One-Class SVMs12

1 1 1-4244-0525-4/07/$20.00©2007 IEEE 2 The research is supported by Air Force Office of Scientific Research, grant number: F496200310174, technical monitor Dr. Clark Allred and NASA Ames Research Center, technical monitor Dr. A. N. Srivastava. Their support is gratefully acknowledged. Abstract— Damage characterization through wave propagation and scattering is of considerable interest to many non-destructive evaluation techniques. For fiberreinforced composites, complex waves can be generated during the tests due to the non-homogeneous and anisotropic nature of the material when compared to isotropic materials. Additional complexities are introduced due to the presence of the damage and thus results in difficulty to characterize these defects. The inability to detect damage in composite structures limits their use in practice. A major task of structural health monitoring is to identify and characterize the existing defects or defect evolution through the interactions between structural features and multidisciplinary physical phenomena. In a wave-based approach to addressing this problem, the presence of damage is characterized by the changes in the signature of the resultant wave that propagates through the structure. In order to measure and characterize the wave propagation, we use the response of the surface-mounted piezoelectric transducers as input to an advanced machine-learning based classifier known as a Support Vector Machine.