Seismic Performance and Strong Earthquake Collapse Analysis of Long-Span Space Suspended-Dome Spoke-Type Truss Structures

In order to analyze the collapse of long-span space structures subjected to strong earthquakes, SAP 2000 software was used to model and analyze the seismic performance of a gymnasium in Xi’an University. Firstly, the natural vibration characteristics of the structure were analyzed, and the low-order mode and natural vibration period of the structure were understood. Subsequently, the seismic performance of the structure was investigated through the response spectrum analysis of mode decomposition. On this basis, the elastoplastic time-history analysis of the structure was focused on, and the plastic development process of the structure under different peak seismic waves was deeply discussed. According to the maximum deformation of the structure, combined with the number and state of plastic hinge, whether the structure could meet the expected capability target of the structure under the specified seismic load was determined, and the response laws of the structure were summarized. The method of determining whether the structure collapsed was obtained. The results showed that the structure had good seismic performance under the action of 8 degree earthquake and rarey occurred earthquakes. Under the action of three-way input RSN55_SFERN seismic wave, the structure did not collapse when the peak value of seismic wave was 1 000 cm/s². Under the action of artificial fitted seismic wave of unidirectional rarely occurred earthquakes, when the peak value of Y-direction input seismic wave was 1 400 cm/s², more than half of the lattice columns completely failed at 7.3 s, and the overall maximum displacement of the structure was 2.2 m, which indicated the collapse of the structure. Under the action of artificial fitting seismic waves of a three-way major earthquake, when the peak value of local seismic waves was 600 cm/s², almost all the lattice columns of the main library failed at 20.8 s, nearly half of the auxiliary columns failed, and the overall deformation of the main library exceeded 2.72 m. Based on the hinge and deformation conditions, the structure collapse was determined at this time. The plastic hinge distribution of the structure occurred on the lattice column and the chord member of the central main truss. It is necessary to investigate the multi-directional seismic wave action when investigating the seismic and collapse resistance performance of long-span structures.