A three-dimensional theory of doubly-curved cross-ply laminated thick shell panels is developed via an energy approach for nonlinear impact model analysis. The simply supported shell panel is strictly stress free everywhere over all four edges and both both lateral surfaces except for the patch loading area where stress/loading equilibrium is maintained. The 3-D dynamic displacement fields are expressed in a mixed mode of in-plane double Fourier series expansion and cubic polynomials in the thickness direction. A system of modified Lagrange's equations is derived incorporating all surface conditions, and continuity of the interface displacements and transverse normal and shear stresses. The nonlinear impact model analysis is performed using the Hertz contact law in patch loading and Green's function for small time steps linearization. The 3-D displacements and stresses are found always unsymmetric with respect to the mid-surface in all cases of unidirectional, symmetric and antisymmetric cross-ply laminates as a result of the one-sided loading a well as the unsymmetric lay-up. By using the maximum stress theory, we are able to predict a tensile crack at the unimpacted side and proably, a delamination at the interface.
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