Elastic Waves in Solids 1. Daniel Royer

      D : electric induction (displacement) vector.

      E : Young modulus.

      E : electric field vector.

      ec (ep) : kinetic (potential) energy per unit volume.

      eijk (εij) : piezoelectric (dielectric) constants.

      F : force density per unit mass.

      H(t) : Heaviside step function.

      I : acoustic intensity.

      J : Poynting vector.

      K : bulk modulus.

      k (k) : wave vector (number).

      KM : electromechanical coupling coefficient (mode M).

l : unit vector normal to a surface.

      n : unit vector of the propagation direction.

      P : transported power.

      pa : acoustic pressure.

      p (p₀) : thermodynamic pressure (at rest).

      p , q : polarization vectors.

      Ps (ps) : power supplied by the source (per unit volume).

      r (t) : amplitude reflection (transmission) coefficients.

      R (T) : intensity reflection (transmission) coefficients.

      s : entropy per unit volume.

      s : phase slowness vector.

      T : absolute temperature.

      T : mechanical traction, stress vector.

      u : mechanical displacement vector.

      U : internal energy per unit volume.

      v : particle velocity vector.

      V^e : energy velocity vector.

      V (Vg) : phase (group) velocity.

      VL (VT) : velocity of longitudinal (transverse) bulk waves.

      W (w) : work (per unit volume).

      x : position vector.

      X, Y, Z : crystallographic axes.

Ze (Y) : electrical impedance (admittance).

      

acoustic (mechanical) impedance.

      α : attenuation coefficient.

      

: elastic (piezoelectric) Christoffel tensor.

      δij : Kronecker’s symbol.

      δ(t) : Dirac function.

      

: linearized strain tensor (piezoelectric solid).

      η : viscosity coefficient.

      θi,r,t : angle of incidence, reflection, transmission.

      Θ : dilatation.

      κ : bulk wave velocity ratio (VT/VL).

      λ, μ : Lamé constants.

      ν : Poisson’s ratio.

      ρ : mass density.

      ρe (σe) : electric charge density per unit volume (area).

      σ (σd) : effective (differential) scattering cross-section.

      σ : Cauchy stress tensor.

      ϕ (ψ) : scalar (vector) potential.

      Φ : electric potential.

      χ : decay factor.

      ω : angular frequency.