Thermomechanical behavior of circular steel arches

• Author(s): Gomes, Margarida ; Mesquita, L.M.R.
• Date: 2018
• Persistent ID: http://hdl.handle.net/10198/18356
• Origin: Biblioteca Digital do IPB
• Subject(s): Steel arches; Buckling; Critical load
• Document Type: Conference object
• Language: English
• Contributor(s): Biblioteca Digital do IPB

Description

Circular steel arches are structural members curved in the plane of the applied loads, where the radius of curvature is much higher than the cross-section depth. The main objective of this work is to evaluate the behaviour of circular arches at room and elevated temperatures, like those that can arise from fires. The in plane buckling of arches is analysed numerically, using ANSYS software, considering different domains, linear elastic analysis, nonlinear elastic analysis and nonlinear geometric and material analysis, where the structural capacity of arches are studied in function of the geometric imperfections and residual stresses. The results are compared with those obtained by the simplified methods of Eurocode 3 part 1.1 and 1.2. The circular steel arches considered comprise a parametric analysis for arches with different spans, radius of curvature and opening angle at different temperature values, and subjected to an uniform radial distributed load. The values of the critical compression loads and the collapse loads were obtained for the different arcs, supports and temperatures. For the different geometries, the results allows to define the instability failure modes, symmetric or antisymmetric. It is concluded that increasing the arch height to the span ratio produces a decrease of the elastic critical load and the collapse load of the arch. The collapse mode for shorter arches is due to the formation of a plastic hinge whereas in the long span arches the structure will became instable before plastification, producing in plane instability in its stronger plane.