Three-dimensional semi-analytical model for the static response and sensitivity analysis of the composite stiffened laminated plate with interfacial imperfections

For the stiffened composite laminated plates with interfacial imperfections, the problem of static response and sensitivity analysis was investigated in Hamilton system. Firstly, the meshfree formulation of Hamilton canonical equation for the composite laminated plate with interfacial imperfections was deduced by the linear spring-layer and the state-vector equation theory. And then, based on the equation of plates and stiffeners, governing equation of the composite stiffened laminated plate was assembled by using the spring-layer model again to ensure the compatibility of stresses and the discontinuity of displacements at the interface between plate and stiffeners. At last, a three-dimensional hybrid governing equation was developed for the static response analysis and sensitivity analysis.To demonstrate the excellent predictive capability of this three-dimensional semi-analytical model, several numerical examples were carried out to assess the static responses and static sensitivity coefficients. Good agreement had been achieved between the predictions and the results of finite element code MSC.Nastran. Extensive numerical results were presented showing the effects of the interfacial stiffness on the response quantities and their sensitivity coefficients. Furthermore, distributions along the thickness direction were also presented for the static responses and the static sensitivity coefficients with respect to the material properties and the shape parameters.