Building floor analysis by the boundary element method

In this work, a boundary element formulation to analyse slabs reinforced by beams, combined or not to define a grid sub-system, is proposed. Kirchhoff ‘s hypothesis is assumed for the plate elements. The beams elements are not required to be displayed over the plate surface, therefore eccentricity effects are taken into account. The formulation is derived by assuming a zoned body where beam elements are introduced by degenerating plate sub-regions. After finding properly a single reciprocity for the whole body, the required integral representations are derived. The integral representations derived for this complex structural element take into account the bending and stretching effects of booth structural elements working together. The standard equilibrium and compatibility conditions along interface are naturally imposed. Moreover, the amount of degrees of freedom required along the interfaces is substantially reduced, leading therefore to small and more accurate algebraic system of linear equations. Several examples are then shown to illustrate the accuracy of the formulation, comparing the obtained results with analytical and other numerical solutions.