Finite Element Analysis On Shear Behavior Of Reinforced Concrete Frame Beams In Fire

At present, most of researches on frame beams in fire focus on bending performance,but there are few studies on shear behavior. In order to ensure the safety of the beam under high temperature and to reduce the fire damage, fire research on frame beams with shear behavior is especially important. The analysis results of frame beam shear properties can provide theoretical basis for the design of fire resistance performance of reinforced concrete beams, and it can improve the fire resistance design theory further.Using the ABAQUS software to analyze reinforced concrete framework structure,the design model for a one span, one storey sub-assembly, the section size is250mmx500 mm girder, the column section size of 500mmx500 mm. Because the high temperature effect of reinforced concrete material properties is obvious, so the thermal performance and mechanical properties of the reinforced concrete and concrete under high temperature are summarized, and then the appropriate parameters are selected to analyze the temperature and stress. Because the decrease and loss of material properties at high temperature directly related to the element and structure mechanical behavior in fire,first of all, the finite element analysis model of the shear behavior of reinforced concrete frame beams is established, and the temperature field and the temperature of the steel bar are analyzed. Secondly, to analyze shear mechanism and simulate shear deformation under normal temperature. Finally, The result shows that the concrete strength, the shear span ratio and the concrete protective layer thickness influence the frame beam shear performance and compare with shear performance under normal temperature. Based on the relevant theoretical research results, summarizing the rules and providing theoretical support for fire resistance design so as to facilitate the engineering practice.