| Every year in our country, a large number of economic and property damage and casualties are caused because of fire. According to the existing situation, the trend will increase year by year. So it is urgent to study the fire resistance of building structure.At present, domestic studies of frame beam of fire-resistant performance is about flexural performance, while the study of frame beam shear resistant property is not sufficient. As the mechanical properties of reinforced concrete beams are greatly affected by mechanical properties of frame beams, the influence of the thickness of different steel bars on the shear performance of frame beams is studied. The main contents and results are as follows:First, carefully collect the latest research on the shear resistance and structure of the beam, then determine the accuracy of the research project.Read relevant literature both at home and abroad to learn thermal parameters and mechanical properties of concrete and steel in fire and after fire, then estimate the constitutive relation of concrete and steel in different temperatures. Then, use ABAQUS finite element analysis software to obtain concrete temperature field and temperature distribution of reinforced bar of different thickness of reinforcement protection layers. The sizes of the structures are completely the same, only the thickness steel bars are different, so the temperature change of steel bars should be compared. Finally, use ABAQUS finite element analysis software to analyze the effect of different steel bar thicknesses on shear behaviors of the frame beams in normal temperature. Then the analysis of the temperature field has been lead into another model to study shear resistance of frame beams in fire and after fire. |
