Meshless numerical simulation of steel connections: application to the T‐stub component

Abstract

AbstractFinite element analysis is a widely used simulation technique in steel design to analyze the structural behavior of structural components, such as beams, columns or connections. The major steps involved in finite element simulations are the definition of the basic parameters and the discretization in elements of the component, also known as preprocessing; the analysis of the model and the post‐processing by the representation and the interpretation of the obtained results. On the particular case of bolted connections, the most time‐consuming of these three phases is that of preprocessing, because on traditional finite element technology is required that the real geometry of the CAD model is simplified to be meshed and analyzed; this task is specifically severe and requires paying close attention on the case of components affected to concentration stresses. Nowadays, different techniques have been proposed and developed with this objective: reduce costs in terms of time and specialized human resources because the workflow is easier and simpler. One of these methods are the known as the meshfree methods, that do not require connection between nodes and are based on the interaction of the points of the geometry with the neighbors, so the processor analyzes taken as base the real CAD geometry and no simplifications are needed.On this paper is exposed the meshless method based on the theory of external approximations as an alternative to the classic finite element method. This method is based on the theory where all parts of the assembly are considered as different elements, and the approximation of displacements inside is arbitrary and not only by polynomials. The convergence of the simulation model is based on the external equilibrium of the assembly. The method is applied to a practical case: the simulation of the T‐stub connection. The T‐stub component corresponds to one T‐shaped steel profile bolted through their flanges and loaded through their web until collapse, and its behavior is similar to the tension zone of beam to column bolted end plate connections. The analysis of strength, stiffness and ductility have been widely investigated experimentally, by simulation and theoretically, and they are obtained from the force‐displacement characteristic curve. Information presented by Bursi and Jaspart on the paper “Benchmarks for finite element modelling of bolted steel connections” are considered to elaborate the models and to compare the results.