Comparative study on measurement of elastic constants of wood-based panels using modal testing: choice of boundary conditions and calculation methods

Journal of Wood Science

Official Journal of the Japan Wood Research Society

Table 2 Selected boundary conditions and corresponding calculation method

Boundary condition	Calculation method	Sensitive modes	Note
FFFF	Closed-form frequency equation by Rayleigh method with one-term deformation expression	(2, 0), (1, 1), (0, 2)	Can be used as initial values for finite element modeling
FFFF	Finite element modeling updating by ABAQUS with S4R shell element	(2, 0), (1, 1), (0, 2)	S4R shell element includes the effect of transverse shear deformation
SFFF	Closed-form frequency equation by Rayleigh method with one-term deformation expression	(m ≥ 2, 1), (1, 1), (0, 2)	f _{(3, 1)} is used for calculating E _x
SFSF	Improved frequency equation by Rayleigh method with three-term deformation expression	(2, 0), (2, 1), (2, n ≥ 2)	MATLAB-based iteration process

FFFF represents the boundary condition of all sides free, SFFF represents the boundary condition of one side simply supported and the other three free and SFSF represents the boundary condition of a pair of opposite sides along minor strength direction simply supported and the other pair along major strength direction free