Influence of Compliance of the Connection of Reinforced Concrete Structures in the Analysis of Progressive Collapse Hazard

Abstract

The results of a numerical study of a fragment of a reinforced concrete frame of a multi-storey building with a special impact in the form of a sudden hypothetical removal from operation of one column are presented. For a more rigorous assessment of the stress-strain state of reinforced concrete frames of multi-storey buildings, it is proposed to take into account the elastic-plastic work of the junctions of structural elements. Two options for connecting a crossbar with a column are considered: the first is absolutely rigid, the second is taking into account nonlinear compliance in the areas: "bending moment-angle of rotation", "transverse force-deformation", "longitudinal force-deformation". According to the results of numerical analysis, a change in internal forces (up to 30%) in the elements of reinforced concrete systems is shown due to the non-linear operation of both structural materials and the geometric non-linearity of the change in the dimensions of the design model due to the compliance of nodes. The revealed differences in the nature of the change in the stress-strain state are explained by an increase in the plastic properties of the carrier system. The established phenomena require further experimental verification, taking into account various types of structural element connections.

Keywords

• progressive collapse
• reinforced concrete structures
• dynamic reloading
• survivability
• special limiting state
• physical nonlinearity