Seismic Collapse Analysis And Seismic Performance Evaluation Of Reticulated Shell Structure On AP Method

Earthquake is a natural disaster that pose a significant threat to human life and occur relatively frequently.The destructive force of earthquake is immense,and the collapse of any structure can result in catastrophic consequences.In recent years,large space steel structures collapsing incidents have led to substantial economic losses and casualties.These incidents demonstrate that despite the complexity of such structures,sudden failure of certain components can trigger structural collapse.Therefore,it is crucial to consider the impact of component failure during the design phase to prevent sudden structural failure during normal usage.Furthermore,single-layer reticulated shell structures have low redundancy and are highly sensitive to defects,necessitating continuous collapse analysis and seismic performance evaluation to ensure their safety.The main research content and conclusions are as follows:Firstly,a method for selecting critical components for large space structures is proposed and failure simulation analysis is conducted on these components.By evaluating the impact coefficients of the components,the distribution of critical components for a single-layer reticulated shell structure is determined.To validate the methodology,an element birth and death method is used to simulate component failure.Structural bearing capacity and stiffness are analyzed to quantify the impact of member failure on the overall structure.The results indicate that the importance coefficients can reflect the degree of importance of the components to the overall structure.Secondly,the progressive collapse resistance of single-layer reticulated shell structures under the failure of vulnerable components was investigated.The distribution pattern of weak areas and dynamic response of the structure were determined using the Incremental Dynamic Analysis(IDA)method.The most critical response parameters such as stress,plastic strain,and equivalent plastic strain were used to identify the vulnerable components.The Alternate Path(AP)method was applied to analyze the dynamic response of the remaining structure under subsequent earthquake actions.The results indicate that the seismic weak area of the singlelayer reticulated shell structure is located at the bottom,where it is subjected to significant seismic effects.Due to the initial failure of the components,significant plastic deformation occurs at both ends,and the plastic development of the surrounding members is evident.Attention should be paid to the components located in the seismic weak area,as their initial failure can have a significant impact on the structure.Finally,the impact of critical component failure on the overall seismic performance of the structure was explored,and a method for evaluating the seismic performance of the structure was proposed.By studying the weak parts of the structure under multiple earthquake actions,the distribution of vulnerable components in the single-layer reticulated shell structure was obtained.Key components were selected based on the importance coefficients of the components,and the seismic performance of the structure after the failure of the key components was analyzed using the fragility curve.The study shows that the initial failure of components should be considered in the seismic design of structures,and component failure can increase the probability of collapse under seismic conditions,which will have a significant impact on the evaluation results of the seismic performance of the structure.