Calculation of Composite Panel Multilayer Structures in Construction Systems

Abstract

Precast-monolithic frame house building, use of stay-in-place formwork technology, improvement of concrete quality by means of additives and introduction of new materials are all innovations in the scope of high-rise construction. Thin wall panels formed by outer layers of structural steel sections and inner layers of concrete are used as structural elements of frame structures. The solution of structure elements strength problems is related to a stress–strain state analysis. Significant difficulties arise in calculation of structures having a complex geometric shape with different combinations of loads. Thin wall composite systems are referred to as such structures. Reinforcing structural elements in composite plates and shells, such as stiffeners and reinforcement, lead to the fact that the structure becomes piecewise inhomogeneous. Constructive heterogeneity occurs in anchor connection of layers as well. Mathematical modeling of multilayer structures is carried out according to the methodology of the composite plates and shells theory. The nonlinear straining mathematical model takes into account shear stresses in joints. The solution of the problem was carried out in the force functions using trigonometric Fourier series. A composite structure formed by three plates with anchor connections of layers has been calculated. The outer layers are steel, and the material of the inner layer is concrete filler. The variation effect of the forces that fall on each individual anchor depending on the stiffness of the anchor connections has been studied. The stress–strain state of the steel-concrete structure has also been studied. The effects associated with variations in the stress state because of the relationship of the steps between the anchors in two orthogonal directions, or the number of anchor connections in the joints, have been revealed. Anchor connections ensure compatibility of different layers of a composite construction, but there are problems of strength of the very anchor due to shear forces in the anchor areas where there are concentrated loads.