B	sample width
fn	fundamental frequency of the nth flexural vibration mode
fT	fundamental frequency of the torsional vibration mode
H	sample thickness
J	(B2 + H2)/12
k	sum of the $\left(\tanh \left(2n-1\right)\pi B{\left(G_{xz}/G_{xy}\right)}^{\frac{1}{2}}/2H\right)/{\left(2n-1\right)}^5$ value from n → 1 to ∞
K	$B{H}^3 \left[1-192H{\left(G_{xz}/G_{xy}\right)}^{\frac{1}{2}}k/\left({\pi }^{5}B\right) \right]/3$
mn and F(mn)	coefficients corresponding to the nth flexural vibration mode
Ex	Young’s modulus in the x-direction
Gxy	in-plane shear modulus in the xy-plane
Gxz	out-of-plane shear modulus in the xz-plane
L	sample length
s	Timoshenko’s shear factor
X and Y	parameters required for calculating the Young’s modulus and shear modulus by the TGH method from the data of flexural vibration tests
a and -b	slope and intercept obtained by the linear regression of 12rJLfT2/H4–B/H relation
r	sample density
AFPB	asymmetric four-point bending
ANOVA	analysis of variance
EPS	expanded polystyrene
FE	finite element
FFT	fast Fourier transform
FV	flexural vibration
L, T, and Z	length, width, and thickness directions of the panel, respectively
RC	resonant column
TGH	Timoshenko–Goens–Hearmon
TVSP	torsional vibration of square plate
XPS	extruded polystyrene