Analysis of the hardness of node connections of metal constructions using modern CAE-systems

Abstract

In classical structural mechanics, there are two types of nodal connections – rigid and simple joints. This separation is used to simplify the calculations of building structures. Methods of calculation of building structures were created based on idealized models. The accuracy of the solution obtained by these methods depends on how closely the physical nodal connection corresponds to its simplified model. To obtain reliable solutions in the calculation of building structures should pay special attention to the correct idealization of nodes. It is known that any idealization leads to a loss of solution accuracy. With the help of modern computers we are able to take into account more specific features of designs in their design models. Evaluation of node stiffness can be performed by experimental methods. The authors see the way to assess the rigidity of the node performing numerical studies using modern CAD as the simplest and promising. Received final design decision will have more credibility and as a consequence have greater reliability and economic efficiency. The approach proposed by the authors to assess the stiffness of the nodes was implemented in the calculations of various designs. For the metal frame, consisting of columns and beams, the authors performed a numerical analysis of the coupling node. For the column support unit on the Foundation, the authors performed numerical studies of two variants of the structural design of the units. The first option is a node consisting of only one base plate. The second-a node consisting of a base plate and low traverse. Numerical studies of the nodes were performed by the finite element method (FEM) using the CosmosWorks calculation complex. The authors found all the nodes to have a finite stiffness; node coupling of beams with the column, performed only through the wall of the beam, has a low stiffness and is actually hinged; the rigidity of the column support unit on the Foundation through the base plate depends primarily on the thickness of the plate.