Analysis Of The Effect Study Of The Joints On Resistance To Continuous Collapse Of Steel Frame-composite Floor Structures

Some of the bearing parts in the structure can be damaged due to the accidental load,which damage can cause continuously collapse of the structure,and subsequently lead to severe loss of the lives and properties and adverse impact to the society.Therefore,more and more researchers begin to pay attentions to the ability of the structure against the continuous collapse.Once the vertical bearing part of a structure are of inefficacy,the original path of the load transfer will be damaged,the remaining parts will come into being an effective Rachel Role with the beam/s resting on the inefficacy pillar through the joints,and the internal loads will be redirected,upon which time the performances of the joints play a very important role to the Rachel Role of the structure.However,the most of the researches to the joints are based on a single part or a plane model.While the structure is under loads,the resistance mechanism of the floor will be differed due to the performance of the joints.Whereas some of the scholars stretch their three-dimension integral structure researches mostly under the condition that the central pillar is of inefficacy.This paper will,if the side pillar is of inefficacy,start the continuous collapse research of two sets of steel frame-combination floor through the alteration of the type of the structure joint,and lay a foundation for the FE simulation and theory study in the future.The contents mainly include the three parts as listed below:(1)Conducting two continuous collapse performance researches on the basis that the side pillar of the steel frame-combination floor is of inefficacy and the type of the joints is different,in which research the continuous collapse process of the structure is divided as minor deformation stage,transforming stage and massive deformation stage,and the whole response and mode of damage in the different stage will be analyzed under the condition that the side pillar is of inefficacy.Some advices for the structure design will be raised for reference upon the integrity and stability of the three dimension integral structure of which the type is different.(2)Through the analysis of the research data,the function of flexural action,catenary action and tensile membrane action of the structure will be analyzed separately.And it will be analyzed simultaneously that the state of the redirection of the internal loads during the anti-collapse process while the side pillar is of inefficacy,and the influences of the different type of joints to the resistance mechanism and redirection of the internal loads.(3)Having adopted Izzuddin simplified method to calculate the reaction of impetus of the three dimension integral structure while the side pillar is of inefficacy,put out the amplification coefficient value of the impetus and compared the impetus response of the three dimension integral structure with different types of joint,it is disclosed that different types of joints are of minor influences to the value of amplification coefficient value during the minor deformation stage.