Long-span beam cells. considering the rigidity of the steel and concrete floor slab

Modern methods of modeling and calculating structures and their elements allow us to investigate and analyze the enormous amount of conditions affecting individual structures and structures as a whole. The accuracy of the calculations is just as important as the speed of their performance under conditions of tough competition. To speed up the calculations, various simplifying assumptions are taken, such as, for example, the calculation of beam cells. However, in the case of the use of concrete elements as overlap or monolith, this simplification turns into an extremely gross error. Modern software systems that use the finite element method, in conjunction with the power of modern computing technology, make it possible to create design schemes that are incredible in terms of saturation and complexity. With the increasing complexity of the schemes, and, accordingly, the equations that have to be solved by computer technology, the chance of an error that may appear simply because of the complexity of the scheme itself grows. Therefore, the topic of simplifying calculation schemes is relevant − where it is needed and where it should not be allowed. The purpose of the article is to study the influence of plate elements in terms of FEM on the redistribution of efforts in a beam cell. The result of research, it was found that the simplified scheme is suitable for evaluating the design, albeit with a slight error, but does not take into account the torque, which on large spans can be disastrous. The variant using the universal plate FE is an excellent solution for calculating flexible floors, and evaluating the influence of moments from horizontal forces on beams with a large cross section, and is comparable in speed to the first option. Universal FE shell is a complex mathematical object that takes into account the shear stiffness of the overlap, and can often have a significant impact on the supporting structure, but its application requires an understanding of the subtleties of the structures, and their compliance to the effects. Although this element is capable of a lot when used correctly, its calculation speed is lower than that of FE plate, and with a large number of them it can take considerable time.