$\alpha$	thermal expansion coefficient	$\rho$	density
${\alpha }_e$	effective thermal expansion coefficient	${\rho }_p$	weighted average of mass density
${\beta }_e$	geometrical constant	${\delta }_L$	change in length
${\gamma }_T$	net heat loss rate	$\varphi$	potential
$\vartheta$	experimental power coefficient	$\nu$	Poisson’s ratio
${\kappa }_T$	thermal conductivity	${\omega }_e$	frequency
$\sigma$	tensile stress	$\xi$	variable
${\sigma }_i$	initial tensile stress	$\Delta f$	frequency change
${\sigma }_a$	axial stress	$\Delta k$	stiffness offset coefficient
${\sigma }_{th}$	temperature-dependent thermal stress	$\Delta m$	mass offset coefficient
${\sigma }_T$	thermal stress	$\Delta T$	uniform change