Effect of axial and rotational restraint on performance of composite beams with fire protection coating

This paper presents the behavior of steel-concrete composite beams with fire protection using the finite element software ABAQUS. An extensive parametric study was carried out to verify the influence of the axial and rotational restraint stiffness, the influence of the spans and the influence of the variation of the fire protection coating, topic with few studies by other authors. The focus of this paper was to verify the axial forces on the supports to study the influence of these forces on the surrounding elements: columns and connections. The study shows that axial and rotational constraints have an important influence on the beams. The values of axial forces are proportionally greater as the beam span is increased. Also verified was that the beam behavior does not change with the variation of the fire protection coating. Finally, the study brings a new approach to the importance of investigating the forces of interaction between beams and columns, as theses forces can lead to unsafe design because the compressive forces in the interaction with the columns and the tensile forces in the catenary phase in connections.