1 Phan N D,Reddy J N.Analysis of laminated composna plate using a higher-order shear deformation theory.Int J Numer Method Eng,1985,21:2201-22192 Chen A T.Yang T Y.A 36 DOF symmetrically laminated triangular element wnh shear deformation and rotatory inertia.J of Composite Materials,1988,22:341- 3593 Craig T J,Dawe D J.Flexural vibration of symmetrically laminated composite rectangular plates including transverse shear effects.lnt J Solids Structures,1986,22(2):155-1694 Bhat R B.Natural frequencies of rectangular plates using characteristic orthogonal polynomials in Rayleigh-Ritz Method.J Sound and Vibration,1985,102(4):493-4995 张根全,孙鲁原,王明生.角交铺设厚层板自由振动的里兹法解.工程力学增刊,1993,664-669