A NOVEL HETEROGENEOUS MODEL OF LAYERED STRUCTURES FOR NUMERICAL MODELING AND SIMULATION AT MICROWAVE FREQUENCIES VIA FDTD

Abstract

Numerous destructive and nondestructive techniques using different energy sources have been offered for material characterization. Among the non-destructive testing techniques that suggest monitoring the content of different materials and concrete structures, the techniques using microwaves offer important advantages because they are not radioactive, provide good penetration, provide excellent contrast with rebar and are not affected by ambient temperature. In this paper, a non-destructive testing (NDT) technique is represented to simulate a novel heterogeneous rectangular geometric structures containing different materials such as concrete, pavement, mortar, rebar and soil based on their dielectric properties. Maxwell wave equations are used to simulate how wave propagates in structures with different dielectric properties. For numerical simulation a Finite Difference Time Domain (FDTD) is used and Absorbing Boundary Conditions (ABCs) is proposed to prevent re-entering of propagating waves into the computation domain.