Ferrol, April 23rd, 2024 – Currently, the field of structural design benefits enormously from the use of the finite element method (FEM), a numerical analysis technique that allows simulating the behaviour of structures under different load conditions and geometries. Thanks to the calculation and analysis using FEM, the need for prototype testing is reduced, project development time is reduced and a more detailed and accurate structural analysis is achieved.
The researcher Manuel López and the team of the Structural Analysis Laboratory (LAE) of the Centre for Research in Naval and Industrial Technologies (CITENI), based at the Industrial Campus of Ferrol (CIF) of the University of A Coruña (UDC), achieved an important milestone in the field of structural design: by means of numerical calculation models of finite elements, they formulated an innovative equation that helps to determine the stiffness in three-dimensional joints aparafusadas (beam-column) when additional plates are used to connect the secondary beams to the footing. This is especially useful when these joints occur in an axis other than the main one of the structure, which is called the weak axis of the leg.
His research article, titled ‘A novel analytical formulation for the stiffness of the component column web panel in shear with additional plates in bolted steel joints’, was recently published in the prestigious journal Engineering Structures, ranked Q1 in the Journal Citation Reports (JCR), the index for scientific journals with the highest reputation worldwide.
The current building regulations offer generic guidelines for the calculation and verification of metallic joints. The LAE research is decisive because the European standard applied to the design of steel structures (Eurocode 3) does not contain references for three-dimensional joint components. And a particularly useful 3D configuration is the one that includes additional plates welded between the ones in the leg. These plates have three purposes: to facilitate the joining of the secondary beams in the secondary or weak axis, to avoid interferences in the main axis and to strengthen the support, adding strength and resistance.
The equation that follows this research is innovative because it allows the calculation of the stiffness of a specific component in a metallic joint, the shear beam panel. That is to say, the additional plate welded to the wings of the beam that is subjected to a shear force generated by the forces transmitted by the beam.
In order to define the equation, four experimental tests of beam-column connections were carried out, a finite element model was calibrated with the data obtained and a parametric study was carried out with sixty different configurations. The results show an excellent concordance between the proposed formulation and the data of the parametric study, which suggests that the new formula for the calculation of robustness is effective.
Manuel López states that the equation obtained complements the formulation of Eurocode 3 and thus extends its range of application. This advance allows structural designers to use more types of semi-rigid joints in their projects. In the words of the author, ‘these types of joints behave more flexibly and use less construction material; in short, they are greener and more efficient’.
