Analysis of stress intensity factors in welded joints of steel lattice girders

Abstract

The purpose of this research was to evaluate the behaviour of stress intensity factors (SIF) in welded joints of steel lattice girders. Considering that more than sixty percent of all steel structural failures recorded in the last ten years occurred in these buildings, the research was inspired by the considerable prevalence of failures in these structures [1]. It was specifically hypothesised that joint geometry and fracture configuration had a considerable impact on SIF values, and this hypothesis was tested. One of the goals was to determine the impact of geometric features on crack propagation, and another was to evaluate the stress intensity factor (SIF) for cracks of varying dimentions. Both a complete study of previously obtained numerical modelling findings via the application of the finite element method (FEM) and a critical assessment of experimental validations carried out through the use of photoelasticity and strain gauge methods were included in the proposed approach [2,3]. Specifically, the findings underlined the significance of mixed-mode loading in girder nodes [5,7]. The findings also revealed a considerable rise in SIF with relative fracture length at the same time. In order to contribute to the improvement of the durability of steel lattice structures, the results gave advice for optimising joint design and inspection procedures.