Shape reconstruction of flaws using modified bron approximation in inhomogeneous materia

In recent years, research on propagation characteristic of wave in inhomogeneous media attracts much attention among experts and scholars in various domains. First, mathematic expression for scattering cross section P(ω) in inhomogeneous is deduced. Then, quantization of Kramers-Kronig relation in inhomogeneous medium containing scatterers is given. Based on the frequency change, the phase velocity due to the inhomogeneous material is introduced into two-dimensional Born approximation formula. Finally, this paper reconstructs the flaw shapes in inhomogeneous medium using backscattered ultrasound through experimental method and the results verify the feasibility of flaw scattering theory.