Investigation of Developed Thermal Forces in Long Concrete Frame Structures

Abstract

The objectives of this paper are to review the modeling and design of concrete frame structures for the changing member-temperature loading case and the section gradient-temperature loading case. In addition, the intensity distribution of internal forces resulting from temperature changes and the factors that cause a decrease or increase in these forces was studied. When the temperature of an object changes positively or negatively, its length increases or decreases according to basic physical laws. If an object subjected to temperature change is restrained, internal compression or tension forces are created. Using temperature equations in a finite element structural analysis software package, deformation and internal forces were calculated for 2-D and 3-D frame buildings. In the member-temperature change loading case, conclusions were reached that no matter how high the structure is, only members such as beams and columns on the lowest two stories are substantially affected, but the greater the length or width of the structure, the greater are the force values on the affected members. In the section gradient-temperature loading case, it was observed that the most affected members were the beams on the upper two levels in addition to the facade columns; however, the output forces and moment values were small and sometimes negligible.