The Law Research On Axial Force In The Beam And Beam-slab-column Force For RC Frame Structure

The earthquake disaster investigation shows that the failure mechanism of "strong column-weak beam" in Chinese Code did not obtain the very good implementation. Many factors are related to the phenomenon,mainly as follows:the contribution of floors, the influence of infill walls,high axial compression ratio,the strong beams and overreinforced beams, etc.In addition,the axial force in the beam and the force delivering among column and slab are not included in the structure design,it is necessary to study those influence on the seismic performance of RC structure.Based on the failure mode of RC frame structure,This paper is focused on the analysis of RC frame structure internal force distribution,axial force in the beam and the force delivering among column and slab using ANSYS and Perform3 D software.the main contents of this paper ars as follows:â‘ RC frame structures with different span are designed according to column shear span ratio, beam span ratio, axial compression ratio.The dynamic elastic and dynamic elastic-plastic internal force response are calculated by the ANSYS software.The influence of various factors on the beam axial force are studied using mathematical statistics methods and its effect on the energy dissipation and failure mode of frame structure by Perform 3D;â‘¡A serious of RC frame structures are designed according to the different spans and control parameters.The influence of each parameter on the the force delivering ratio are investigated by analysing the internal forces of the model with and without slabs and regressing the data through the method of mathematical statistics.Lastly its effect on failure mode of frame structure are researched by Perform 3D;Based on the above work,the preliminary conclusions are as follows:â‘ Axial force does exist in the beam and its priority form are axial pressure force.At the elastic and elastic-plastic stage,the ralationship of M-N are linear and nonlinear respectively,the effect of beam span ratio on the axial force are more significant than column shear span ratio and axial compression ratio.Considering the axial force in the beam design can reduce the reinforcement and can effectively improve energy dissipation distribution and failure mode of RC frame structure;â‘¡Throughout the analysis of internal force,we can know that the phenomenon of slab-column delivering force directly does exist and the force-delivering ratio is positively related to slab,column section and negatively related with the beam section. the force-delivering ratio in the 1th floor is bigger than the nummber in the 2th becausing of the different restraint between the two floors.When the structure is under elastic-plastic state, the slabs begin to crack and the force-delivering ratio reduce with the increase of load; Considering the axial force in the beam and the force delivering among column and slab in the structure design can improve the failure mode of RC frame structure;...