Mixed 2D and beam formulation for modeling sandwich structures

This paper presents a new finite element (FE) approach to modeling edge effects in beam sandwich structures. The approach is based on a mixed 2D and beam formulation conjuncted by means of a penalty function method. Several results from analysis of sandwich beams and frames bending with different boundary conditions and laminate properties are solved in order to demonstrate the accuracy of the algorithms and software developed. The influence of the penalty factor on the spectral condition number of the stiffness matrix and on the residual norm of the solution is also investigated for different isotropic and sandwich structures. The FE analysis of complex sandwich beam joint is subsequently presented. Results of this analysis show the advantages of the developed approach for large problems.