Determinação da capacidade resistente a força cortante de perfis i de alma senoidal em em situação de incêndio

• Ano de defesa: 2010
• Autor(a) principal: Aline Lopes Camargo
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Temperatura; senoidal; mecânicas; Engenharia de estruturas
• Link de acesso: http://hdl.handle.net/1843/BUOS-8CJJXP

This work presents an analytical and numerical analysis of shear strength for I-girders sinusoidal corrugated web at elevated temperature. At room temperature, the corrugation increases the shear strength of the web, thus avoiding failure of the beam due to loss of stability before the plastic limit-loading for the web is reached. The main focus of this work is the behavior of the web under fire conditions. A simple analytical procedure is proposed to verify the shear strength of the web at elevatedtemperatures. Considering the deterioration of material properties, the equations for room temperature was expanded to elevated temperature.Analytical results were compared with Finite Elements (FE) analysis, using the computational program ABAQUS. It was considered isothermal conditions at room temperature, 400ºC, 550ºC and 700ºC. The boundary conditions at the edges of the web panel simulated transverse stiffeners. For room temperature, the load was applied until the collapse of the web panel; and at elevated temperature, the temperature was increased through the degeneration of the material properties and then the load was applied until the collapse. The numerical analysis with the EN 1993-1-2:2005 stress-strain relationship was able to simulate the behavior of slender elements, in this case, the sinusoidal web. However, the analytical analysis had to be adjusted to reproduce these results. Thus, it was adjusted the retention ratio of the yield strength. Through the results, it was found a retention ratio at 0.5% of deformation based on the EN 1993-1-2:2005 stress-strain relationship for the 2 mm web thickness. This retention ratio is close to that recommended by the BS 5950 - Part 8: 1990, and is also similar to the retention ratio for class 4 sections of theEN 1993-1-2: 2005.In conclusion, is proposed a simple analytical procedure to predict the ultimate shear strength at elevated temperatures for corrugated web beams, applying only the appropriated retention ratios for the material properties at elevated temperatures. Key words: corrugated web plate, shear strength, elevated temperature.