Objective  To lay the foundation for the comparative study on vibration testing results of elastic constants for full-size oriented strand board (OSB) panel under these three boundary conditions, the modal sensitivity and vibration mode of full-size OSB panel under completely free boundary condition, supported on four nodes and simply supported on two opposite sides were studied, respectively.

  Method  Full-size OSB panels with 4 kinds of thicknesses were used as study object. The modal sensitivity analysis of full-size OSB panels under these three boundary conditions was carried out using finite element software COMSOL Multiphysics, and the modes with the highest sensitivity corresponding to their three elastic constants including modulus of elasticity (E_x and E_y) in the length and width direction as well as in-plane shear modulus G_xy were obtained; the first nine vibration modal parameters of full-size OSB panels under these three boundary conditions were measured through experimental modal analysis, and the testing results of their vibration modal parameters under three boundary conditions were compared and analyzed.

  Result  The modal shape and order of the first nine mode of full-size OSB panel under three boundary conditions were separately identical through experimental and theoretical modal analysis; except for mode (m, 0), (0, 2) and (1, 1), the first nine modes of full-size OSB panel under three boundary conditions were superimposed modes for bending and torsional in single direction or bending in different directions; the modes with the highest sensitivity for calculating E_x, E_y and G_xy of full-size OSB panel were mode (2, 0), (0, 2) and (1, 1) corresponding to the second, fourth and the first order under completely free boundary condition, mode (2, 0), (0, 2) and (2, 1) corresponding to the first, fourth and the third order for being supported on four nodes, mode (2, 0), (2, 2) and (2, 1) corresponding to the first, fifth and the second order for being simply supported on two opposite sides.

  Conclusion  From the perspective of vibration mode, it is feasible for performing the modal sensitivity analysis and vibration modal test of full-size OSB panel under three boundary conditions based on theoretical and experimental modal analysis method.