Continuous Collapse Analysis And Failure Mode Control Of Space Frame Structure

The continuous collapse of the Ronan Point apartment is the beginning of people’s recognition of the continuous collapse and destruction.After that,the continuous collapse and destruction began to gradually come into people’s vision.It was not until the continuous collapse of the World Trade Center in the United States that people truly realized the continuous collapse.The consequences of the destruction have become more and more serious in social impact and economic losses,and researchers are paying more and more attention to the research of such destruction.At present,although some scholars have conducted many experiments and analyses,there are still many problems that have not been well understood and resolved.Generally,due to collision and other reasons,the probability of continuous collapse of corner column failure is relatively high.Therefore,this paper mainly uses model tests and finite element analysis of the reinforced concrete space frame test model to study the continuous collapse resistance of this type of structure under corner column failure.And the corresponding simple control method to improve its ability to resist continuous collapse.The main tasks are:(1)A test model of reinforced concrete space frame with a similarity ratio of 1/3,single-story,two-way two-span,corner column failure was designed,and the continuity resistance of the space frame test model when the corner column failed was studied through the static loading test method.Collapse capacity,the relationship curve between the load of the failed corner column and its vertical displacement is obtained,the corresponding stress and strain development process and distribution law of the corresponding frame beam,slab reinforcement and concrete are analyzed,and the displacement of the failed corner column is discussed.The relationship with the displacement of frame beams and columns.The test results show that when the corner column failure space frame model structure undergoes continuous collapse and failure,the first elastic working stage is experienced,and the structure can work normally at this stage,followed by the plastic stage and the failure stage.These stages of the structure change from gradual yielding to complete collapse.And with the redistribution of internal forces.The entire collapse process shows that the continuous collapse of the failed corner column space frame structure is closely related to the flexural bearing capacity of the structure itself.(2)Using the large-scale finite element analysis software ABAQUS,the finite element analysis model of the reinforced concrete space frame when the corner column fails is established,and the finite element analysis of the corresponding structure is carried out,and the load-displacement analysis curve of the corner column failure space frame structure is obtained,And compared the relationship curve between the load and the vertical displacement of the tested failed corner column and the corresponding relationship curve obtained from the corresponding beam and slab.The results show that the two are in good agreement,indicating the finite element analysis model established in the article And the calculation method is reliable and effective.It can better analyze the failure process and main characteristics of this kind of structure against continuous collapse,and it can be used for the finite element analysis of this kind of structure against continuous collapse.(3)In view of the main characteristics of the continuous collapse failure of the abovementioned corner column failure reinforced concrete space frame structure,based on the above model test and finite element analysis results,the article proposes 4 simple control methods that can improve the continuous collapse resistance of this type of structure.That is,cross beams,long double beams,single inclined beams,and three inclined beams are added at the adjacent beam slab of the failed corner column.Using ABAQUS software,the above four additional simple control methods are analyzed,and the effects of the above four simple control methods are determined by comparing the corresponding space frame structure’s ability to resist continuous collapse.The results show that since the above four methods can all enhance the overall working performance of the adjacent beams and plates of the failed corner column,they can all improve the continuous collapse resistance of this type of structure.The corresponding improvement effects are 7.65%,11.36%,16.23% and respectively.19.38%,it can be seen that the lifting effect of the three-inclined beam method is relatively obvious,which can provide a design reference for the continuous collapse of the reinforced concrete space frame structure when the corner column fails.