Modeling thin-walled elements with regard to steel hardening

Abstract

Today in Russia 13% of buildings are built on the basis of a metal frame. To increase the energy efficiency of the industry, the use of thin-walled steel structures is one of the most technologically advanced and efficient solutions. To ensure the bearing capacity and reduce the risks of failure of buildings and structures at the design stage, it is important to correctly assess the reliability of the system, taking into account all influencing factors. The technology for the production of thin-walled profiles determines the factors that affect their stress-strain state. Uneven distribution of mechanical properties over the cross-section of the profile: hardening in the bending corners and adjacent zones leads to an increase in the strength of the metal. The article presents the results of numerical modeling of samples from thin sheet steel with and without the effect of hardening. The object of research is a thin-walled sigma profile with a section height of 300 mm, an element length of 4500 mm, operating under compression with bending. Metal hardening values are based on experimental data obtained by the authors. The stresses and displacements obtained as a result of the simulation were analyzed in four sections along the profile length: at a distance of 0.5 m, 2.3 m, 3.0 m and 4.0 m from the support. It is concluded that the supercritical work of the element without hardening of the material occurs earlier than in the element with hardening. The maximum stresses in the element without hardening exceed the stresses in the element with hardening by more than 30%. The maximum displacements in hardening are more than three times.