To overcome these constraints, this work proposes a preliminary and broadband wave impedance
equalization of the two guiding geometries, ridged and rectangular, by adjusting the design parameters M and D shown in Fig.
The mechanical properties of the fillings affect the discontinuity degree of the specimen, which was measured by the wave impedance
. The wave impedances
of four media are shown in Table 2 [21-24], where [rho] is the density, c is the longitudinal wave velocity, [eta] is the wave impedance
, and [DELTA][eta] is the wave impedance
The test system consists of a launcher, a punch, an entrance rod (density: 7.810 g/[cm.sup.3], elastic wave velocity: 5410 m/s, and wave impedance
: 4.23 x 107kg x [m.sup.-2] x [s.sup.-1]), and transmissive rod, etc.
Moreover, for a complete ballistic performance evaluation, both the shock wave impedance
and the maximum bullet speed (limit velocity) to withstand by new composites are needed.
where [GAMMA] is the reflection coefficient, [Z.sub.n] is the wave impedance
in the MA material, and [[eta].sub.o] is the wave impedance
Its impedance is [Z.sub.T] = [Z.sub.0]/[square root of [[epsilon].sub.r]], where [Z.sub.0] = 377 [OMEGA] is the wave impedance
in free space and [[epsilon].sub.r] is the relative permittivity of the dielectric substrate.
Denote the variable wave impedance
ratio to describe the nonuniform degree of pile segment; that is, [R.sub.v] represents the ratio of wave impedance
of normal pile segment to that of nonuniform pile segment.
This is because, with the increase of the elasticity modulus of the foam concrete, its wave impedance
and wave impedance
ratio both increase.
In this case method of moments (MoM) for calculation of the wave impedance
and effective permittivity in case of odd- and even- excitation [Z.sub.e], [Z.sub.o], [[epsilon].sub.e] and [[epsilon].sub.o] is used.
In (2), k is the complex propagation constant of a particular mode along the periodic grating structure, and ko and no represent the wave number and wave impedance
where [Z.sub.1] = [square root of [[mu].sub.1]/[[epsilon].sub.1]] is the characteristic wave impedance
of the coating; [Z.sub.2] = [square root of [[mu].sub.2]/[[epsilon].sub.2]] is the characteristic wave impedance
of the material under the coating; [k.sub.1] = [omega] [square root of [[epsilon].sub.1][[mu].sub.1]] is the wave number inside the coating; [[theta].sub.1] and [[theta].sub.2] are angle of transmission in the coating and conductor, respectively; d is thickness of the coating.
We then take into account the boundary effects due to the excess polarization and magnetization induced at the interface, which are approximated by electric and magnetic susceptibilities, to derive the equation that extracts the effective wave impedance
of a metamaterial for the case of a wave impinging obliquely on a metamaterial slab.