The structural materials, as reinforced concrete, steel, wood and aluminum, when heated have their mechanical proprieties degraded. In fire, the structures are subject to elevated temperatures and consequently the load capacity of the structural elements is reduced. The Brazilian and European standards show the minimal dimensions for the structural elements had an adequate bearing capacity in fire. However, several structural checks are not contemplated in methods provided by the standards. In these situations, the knowledge of the temperature distributions inside of structural elements as function of time of exposition is required. The aim of this paper is present software developed by the authors called ATERM. The software performs the thermal transient analysis of two-dimensional structures. The structure may be formed of any material and heating is provided by means of a curve of temperature versus time. The data input and the visualization of the results is performed thought the GiD software. Several examples are compared with software Super TempCalc and ANSYS. Some conclusions and recommendations about the thermal analysis are presented

Most cold-formed steel columns display open and rather thin-walled cross-sections which mean that their structural behaviour is strongly affected by local and global buckling. Th e local mode, that occurs for shorter profi les, is characterized by (i) the local plate mode (LPM) characterized by the simultaneous flexural buckling of the web and fl anges and (ii) by the distortional mode (DM) characterized by the displacements of flange-stiff ener edges (that remain plane). The global mode occurring for long profi les is characterized by (i) the fl exural mode (FM) characterized by the translation of the whole section in the direction of the major principal axis and (ii) by the fl exural-torsional mode (FTM) characterized by the simultaneous translation and rotation of the whole section. Th e possibility of using the results of linear stability analysis in the national codes of thin-walled cold-formed steel structural elements (for instance, European and Brazilian Codes) arises, i.e. local and global buckling instability modes and corresponding bifurcation stresses determining the ultimate strength of members. Two powerful numerical methods are chosen to perform a linear stability analysis of a cold-formed steel structural member: (i) the Finite Strip Method, (i1) the Semi-Analytical Finite Strip Method (trigonometric functions are used in the approximation of displacement) used for simply supported boundary conditions, (i2) the Spline Finite Strip Method (‘spline’ functions are used in the approximation of displacement) used other boundary conditions and (ii) the Finite Element Method. The linear local and global stability results of for Z, C and rack cold-formed columns are used to obtain ultimate strength through the procedures adopted in the Eurocode 3, Part 1.3 and in the Brazilian Code (NBR 14.762/2001). The obtained numerical estimates by specifi cations are compared with experimental results available in literature.

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