Avaliação estrutural de cantoneiras em aço inoxidável austenítico submetidas à compressão

Abstract

The stainless steel has been used in various types of buildings due to its characteristics like high corrosion resistance, durability, appearance and aesthetics. The current design of stainless steel standards is still based on carbon steel structures analogies. Despite its geometric simplicity, columns characterized by cross-section-type equal-leg angle exhibit a particular structural behavior, once these elements show interaction between two overall buckling for flexural-torsional and flexural minor-axis. The flexural-torsional buckling phenomena is associated with an approximately horizontal plateau of axial critical load as a function of length, exhibiting a distinct behavior within this plateau. Thus, it can be observed that both the material and cross-section equal-leg angle have gap that need to be filled. This study shows an experimental and numerical analysis of fixed-ended hot-rolled austenitic stainless steel 304 equal-leg angle section columns. The testing scheme was conducted on three angle sections, as: L76x76x6,4; L64x64x4,8 e L64x64x6,4, where the nominal columns lengths for each cross-section were selected by an elastic critical buckling analysis by the GBTul program. Material testing was carried out by tensile and compressive loading, and subsequently geometrics imperfections measurements to determine the initial global (major-axis and minor-axis) and local (torsional) along the prototypes length. Experimental results include failures modes, equilibrium paths and columns ultimate load. This was followed by a parametric numerical study, where the developed numerical models were validate by the experimental results in ANSYS 17.0 and utilized to generate additional results over a broader range of member lengths and cross-section dimensions usually used. Comparing the results of the numerical analysis to the Eurocode 3 - Part 1.4 design curve and the method developed by Dinis and Camotim (2015) based on the Direct Strength Method, it was concluded that the current standards procedures do not provide a suitable design, therefore a modified design method was proposed in this study, based on the procedure used by Eurocode 3 - Part 1.4.