The Dynamic Time-history Analysis Of A Steel Frame-Bracing Sandwich Rigid Frame

While China’s economy developed rapidly, the construction industry expansion frequently with economic changing together.In order to meet the immediate needs, building structure has become increasingly diverse.Steel structures get more and more recognized by structural engineers in the present moment.In structural design,the most important issue to consider is the structure security. Structures under accidental loads that would damage the local structure,cause local carrying capacity missing, thus spread to the adjacent part of the structure continues,until the main structures lost the carrying capacity,large-scale structure of the chain reaction caused by the collapse occurred is called progressive collapse.Progressive collapse of the building can cause very serious loss of life and property caused huge social impact, the consequences are very serious.However, the design requirements in specification of the structure of the progressive collapse is still very vague,So,analysis of the progressive collapse of the steel structure has a certain social significance.In this paper, research work in the following areas:The first chapter describes the meaning of structure of the progressive collapse resistance ability,listed the typical instances of progressive collapse of the building at home and abroad, described in detail the corresponding specification enacted and regulations which researched and analyzed made by predecessors,and presented related research programs in this article.The second chapter define the progressive collapse resistance ability of structures, described in detail the design criteria for progressive collapse resistance ability,According to the related design criteria analysis of structural progressive collapse event customized by Anglo-American countries, proposed design specifications made according to the mechanism of structural collapse,and the conceptual design methods and the allowed range.of structure localized collapse.analyzed the conceptual design methods of the progressive collapse resistance of structures, according to the understanding of the specification made a relatively detailed introduction.Finally, make a note to analysis of the four means of the alternative load path method of structural progressive collapse ability.make the well theoretical foundation for the below analysis.The third chapter according to the steel frame structure model and model-derived operating conditions, through comparative analysis of internal force distribution,research the structural change rule in the internal forces.Through the nonlinear static analysis of structure,analyzing the impact of different positions member of damage caused by different levels of member structure.Based on the results of nonlinear static analysis,proposed the design to improve the structure redundancy,select a relatively large impact analysis of working conditions,inferred that should adopt various methods to the structural design in a parallel manner,ensure the structural bearing capacity requirements.The forth chapter working the nonlinear dynamic time history analysis of the original model of steel structures and the various of conditions, analysis of the conditions of the order and the time of the plastic hinge,comparative results for loads affected relatively largest working conditions.By comparing the different conditions when the internal force time-history curve, analysis of the structural undertake load situation and internal force metastasis in member after failure,study the impact on structure progressive collapse resistance ability. Analysis of the structure of each element model and working conditions displacement response and acceleration response,compare the situation of displacement and size of the inter layer displacement angle,infer the nonlinear dynamic analysis process most affected by the relative conditions,take measures to improve the working conditions.The fifth chapter mainly summarized the contents of this paper,proposes deficiencies content in this paper,make certain prospect of future research work carried out direction in this paper.