Abstract : As a prerequisite to nondestructive testing of damaged fibered laminates, the
Green’s function, corresponding with an undamaged structure, and the electromagnetic
fields associated with the damaged one are investigated herein.
For the undamaged fibered laminate, benefiting from the periodicity of the
fibers within each layer, the field solution follows the scattering-matrix-based
method using the Floquet theorem. Yet, the periodicity is destroyed by the
analytical source (for the Green’s function) or by damages, and the Floquet
theorem cannot be directly applied to compute the associated scattering matrices.
The array scanning method is introduced to that effect. Inserting fictitious
sources to get a quasi-periodic source array, the modeling approach for undamaged
laminates can be used to compute the field with the source array, the
integration of which cancels the effects of the fictitious sources and yields the
Green’s function. With the multipole method, field disturbances by damages,
which include missing, displaced, shrunk, and expanded fibers and circular
inclusions inside fibers, are accurately modeled by setting equivalent sources
inside sound fibers, and the array scanning method applies. Modeling accuracy
and efficiency of the approaches are illustrated by numerical simulations.
