Analysis Of Progressive Collapse Resistance And Robustness Evaluation Of Frame-supported Shear Wall Structure With Beam Conversion Layer

Since the collapse of the Ronan Point apartment in 1968,the problem of progressive collapse of the structure has received much attention from the engineering community.Experts and scholars at home and abroad have made in-depth research in relevant fields and achieved fruitful results,but at present the research objects are mainly limited to the typical frame and frame-shear structure.With the universal application of the conversion layer structure,its security issues cannot be ignored.However,it is necessary to further explore whether the collapse failure mode and the research results of the frame structure are suitable for the transition layer structure.Due to the existence of the conversion layer,the force condition of the overall structure is complicated,and the up and down force transmission mechanisms are not coherent.It lacks a reliable analysis process and a practical evaluation method in terms of resistance to progressive collapse.Therefore,the anti-collapse simulation of the conversion layer structure can not only improve the related research,but also provide a reference for the current anti-collapse design specifications in my country.In this paper,based on the alternate load path method,the frame-supported shear wall structure with beam conversion layer is taken as the research object,and its progressive collapse resistance analysis and robustness evaluation are carried out.The main research contents and analysis results are as follows:(1)With reference to a two-story single-span frame-supported shear wall plane test model,through finite element modeling and analysis to verify the applicability of beam-column member plastic hinge eigenvalues and shear wall layered shell elements,we obtain numerical values The analysis results are almost in agreement with the test results,which provides a basis for the nonlinear analysis of the frame-supported shear wall structure.(2)Based on the method of alternate load path,a frame-supported shear wall structure with a beam conversion layer is taken as the research object.Different failure conditions are selected in the frame supported floor for nonlinear dynamic analysis.The vertical displacement change of the upper node of the failure column and the redistribution of the internal force of the remaining structure are investigated.Then the resisting mechanism and the law of stress of the frame supported shear wall structure are summarized.The analysis result is:According to the comparison of the deformation of the failure point under various conditions It is learned that the displacement of the first layer is greater than the displacement of the conversion layer,and the corresponding displacements of the failure of the column at different positions on the same layer are from the largest to the smallest,the corner column,the inner column,the long side center column,and the short side center column.(3)In order to evaluate the progressive collapse resistance of frame supported shear wall structure from a quantitative perspective,based on the vertical IDA analysis method,according to the load coefficient displacement curve obtained under different failure conditions,the damaged strength ratio,residual influence factor and strength redundancy factor of the structure are used to quantitatively evaluate the redundancy of the residual structure after the failure of different components of the frame supported shear wall structure The influence of local failure on the continuous collapse resistance of the structure is analyzed.From the analysis results,it can be seen that the stiffness of the conversion layer member is large but the overall ductility of the structure is reduced,so in the design stage of such structures,attention should be paid to the effective combination of the stiffness and ductility of the structure;under normal use,the failure conditions assumed by the structure in the text There will be no collapse at the bottom,and it has good robustness.(4)According to the research content of this paper,combined with the stress state of the frame-supported shear wall structure under vertical load,specific measures for avoiding continuous collapse of similar structures and improving structural robustness.is mainly given from different aspects such as structural layout,special component design,key component design,and tie-up effect between components.