A New Seismic Damage Assessment Method for Single-Layer Spherical Reticulated Shells Based on Structural Residual Displacement under Sequential Earthquakes

Single-layer Spherical Reticulated Shell (SSRS) is usually utilized as an emergency shelter or a command post for disaster relief. However, the structural damage indicators in current studies are difficult to observe or record so as to hardly assess the damage state after the main shock. In order to explore the damage state assessment timely and accurately for SSRS, a new seismic damage assessment method based on structural residual displacement under main shock-aftershock ground motions is proposed in this paper. The finite element model of Kiewit 8-SSRS (K8-SSRS) is established in the ANSYS with 40 groups of actual sequential earthquake from the Pacific Earthquake Engineering Research Center (PEER) seismic database. Then, the dynamic responses of the model are analyzed to calculate the damage index and eight structural dynamic response indicators. Moreover, the correlation study between the damage index and eight indicators is carried out to make the comparison analyses. Finally, it is verified that the structural plasticity appeared under main shock can develop further under strong aftershock to cause greatly additional damage or even result in structural strength failure. It is concluded that the maximum residual displacement has the strongest correlation with the damage index of the structure under sequential earthquake, which means the most feasible indicator to characterize the structural damage under sequential earthquake.