h f	The thickness of the film
H	The thickness of the substrate
v f	Poisson’s ratios of the film
vs	Poisson’s ratios of the substrate
${\overline{E}}_{\mathrm{f}}$	The equivalent Young’s modulus of the film
${\overline{E}}_{\mathrm{s}}$	The equivalent Young’s modulus of the substrate
u	The axial displacement function
εx	The central axial strain of the thin film
ε	The strain of the thin film
w	The lateral displacement of the thin film
t	Time
A(t)	The time-varying wrinkle amplitude of this structure
k	The characteristic wave number
U b	The bending energy of the film
U m	The membrane energy of the film
A	The abbreviation of A(t)
U s	The strain energy of the substrate
U total	The total energy
$\dot{A}\left(t\right)$	The first derivative of A(t) with respect to t
$\ddot{A}\left(t\right)$	The second derivative of A(t) with respect to t
E	The total kinetic energy of the film/substrate structure
ρ f	The density of the film
ε applied	The amplitude of the external excitation strain
ε pre	The pre-strain
κ	The curvature of the substrate
c	The damping term
ω	The frequency of the external excitation
$\overline{\omega }$	The dimensionless frequency of external excitation
τ	The dimensionless time
$\overline{c}$	The dimensionless damping coefficient
$\overline{W}$	The potential energy function
ε fracture	The fracture strain
ε peak	The peak strain