Otimização do Desempenho Estrutural de Vigas Alveolares de Aço em Condições de Incêndio

Given the research capabilities of the members of the IPB and UA research teams, the primary objective of this project is to investigate cellular beams at elevated temperatures, both experimentally and numerically, to propose new simplified design rules for this beam in fire situations. In addition to the general objective presented, specific objectives include: • Conducting theoretical studies Conducting theoretical studies involves an in-depth review of existing literature, research papers, design guidelines, and standards related to cellular steel beams, fire resistance, and structural optimization. The presence of holes in the web of cellular beams significantly affects their stress and strain states. To better assess the behaviour of cellular beams with a combined effect of bending and shear efforts, analytical studies will be carried out to determine the plane state of stress and strain around the circular web openings. This preliminary analysis, combined with the collapse modes achieved in the experimental tests and the numerical simulations, will help with the final proposal of simplified design rules for cellular beams in a fire situation. • Performing experimental tests. Experimental tests are essential for analysing cellular beam behaviour and to be used as a parameter in validating numerical models. The specimens are manufactured according to the planned tests and the intended collapse mode to be simulated. Tests will be conducted under ambient and fire conditions, considering different cellular beams, loading conditions, and temperatures, and will provide new and original results different from those of the few existing in the literature. In addition, the data from experimental tests will be able to be used as a reference by researchers in different works of experimental and numerical studies. • Calibration of numerical models and parametric studies. Numerical models will be calibrated using experimental data, followed by parametric studies with a set of numerical simulations to determine cellular beam resistance at different temperatures. A greater number of beams are considered in parametric studies than in the experimental test, covering several beam spans, loading conditions, cross-section, geometric parameters, and temperatures. These studies will enable a more in-depth analysis of the behaviour of the beams, making it possible to determine the resistance for all different modes of instability and collapse mechanisms. • Formulating design rules based on collapse mechanisms. Due to the requirement for updated design standards concerning cellular beams, this project will formulate each collapse mechanism resistance to propose simplified design rules for cellular beams in fire. The formulation will be carried out by analysing the results of parametric studies based on the material, geometric properties, loading conditions, and temperatures. In addition to proposing a design rule, which has not been available at elevated temperatures until now, the new formulation will consider all the collapse mechanisms, including those caused by openings and those that already existed in the solid beams but are influenced by the openings. By pursuing these objectives, the project aims to enhance the understanding of cellular beam behaviour in fire conditions and contribute to the development of effective design guidelines for improved structural safety.