Preliminary Study On The Realization Of "Strong Column-weak Beam" In RC Frame Structure

In order to make buildings not instantly collapse during the earthquake process,researchers put forward the "strong column-weak beam" design concept.The seismic code use moment amplification factor to ensure the realization of "strong column weak beam" Mechanism,but many seismic damages show that a large number of RC frame structures for various reasons make the column ends generate plastic hinge firstly,forming "strong beam-weak column" mechanism.The seismic damage occurred under the dynamic load(ground motion),rather than the static load in the design,and the seismic force specified in the seismic code is essentially static.The failure modes of the structures under different earthquakes may be completely different.Therefore,100 ground motions are randomly selected to perform dynamic history analysis,providing the suggested reinforcement for structural seismic design.The following is the main work of this paper:(1)Calculating the reinforcement of the structure according to the load,site-type and other factors,establishing nine models with different moment amplification factors,through those can achieve the reinforcement of columns.The models chose the site III.In order to explore the response of the structure under different GPAs,the earthquakes were adjusted to 0.2g and 0.3g.The damage forms of the node are divided into "strong column-weak beam" type and "strong beam-weak column" type,and "strong column weak beam" type is divided into four cases.The nodes are classified according to the symmetry of the structure,the location of the nodes and the constraints of the nodes,providing the basic for the statistics of the various types of nodes.(2)To determine the damage of each node under each earthquake,and the destruction of the form of each node statistics,lists the nodes "strong beam weak column" type of damage to determine the relatively serious damage to the floor,select the floor As the main object of study,the damage pattern of each node of the floor is subdivided to observe the change rule of various failure modes with the increase of the moment of the column bending moment.The number of column hinges is counted separately,The change of the moment coefficient of the end moment,and find the relatively weak column end of each node.(3)The axial force and bending moment of the column end and the beam end are calculated,and the correlation between them is studied.The correlation function between the column end force is given.Observing column end and beam end’s axial force and moment under "strong beam and weak column".A new model is established to verify the correlation curve of axial force and bending moment.