Failure Mechanism Of The Single-layer Cylindrical Shell With Substructure Under Severe Earthquake

The single-layer reticulated dome is a common form of spatial structure with vast potential of future development. It is utilized widely and developed rapidly in recent years due to the good integrity, the light weight, easy assembly and aesthetic beauty. Research work on large span spatial reticulated domes was mainly focused on dynamic behaviors, stability analysis, buckling and path tracking, elasto-plastic large deformation simulation and failure mechanism under severe earthquake. Most of the studies were based on the simplified analytical model that is installed directly onto the ground by pin for the purpose of simplicity. In fact, spatial reticulated domes are usually supported by substructures which are supported by foundation. There will be some deviations in the numerical simulations without the consideration of the influence of substructure and soil. Therefore, according to these practical problems, the failure mechanism and failure control method of reticulated domes with consideration of substructure and soil is studied systemically in this paper. The main research contents are stated as follows:The natural vibration characteristic is the characteristic of the dynamic response of the structure. This paper carried out the consider influence of the stiffness of the substructure of single-layer latticed cylindrical shells on the natural vibration characteristics of, the establishment of the first consider substructure of single-layer cylindrical reticulated shell structure of the whole analysis model, wherein the support structure with elastic material is assumed, then to consider the whole substructure of single-layer cylindrical reticulated shell structure modal analysis, are considered substructure of single-layer cylindrical reticulated shell structure under each mode of vibration frequency. Finally, by changing the single-layer cylindrical reticulated shell structure parameters to consider the whole substructure of single-layer cylindrical reticulated shell structure of large scale parameter analysis of, systematically investigated different parameters on single-layer cylindrical reticulated shells self vibration frequency with the effect.1. Considering the influence of supporting stiffness on the seismic response of single-layer cylindrical reticulated shellsAs the mechanical performance index of the support structure, the supporting stiffness is very important to study the dynamic characteristics of the single-layer cylindrical reticulated shells and the failure of the strong earthquake. Large span spatial structure of the support structure is very rich, this paper uses the different stiffness of the steel column as a representative of the impact of this study. Self vibration characteristics is the inherent structure of the dynamic response characteristics, is an important characteristic in the investigation of earthquake reticulated shell structure failure, so first of single-layer cylindrical reticulated shells structure self vibration frequency in the study on single-layer cylindrical reticulated shells prior to the expiration of the mechanism is also very important. In the specific research program, this paper carried out the first is through the large-scale finite element analysis software ABAQUS to establish the overall research model, in the single-layer cylindrical reticulated shells structure joined the supporting structure, supporting structure of the elastic material assumed that by examining the supporting structure stiffness respectively of reticulated shell structure self vibration characteristics brought impact, in particular to through modal calculation of the whole structure, it is concluded that its self vibration frequency in each mode. Finally, the structural parameters were analyzed, and the influence of the natural frequencies of the whole structure was investigated.2. Response characteristic of single-layer cylindrical reticulated shells with consideration of stiffness of substructure under severe earthquakesSubstructure's stiffness is one of the most important factors which influence the dynamic behavior and failure characteristic of single-layer cylindrical reticulated shells. Therefore, this paper firstly studied the influence of support stiffness on the natural frequency of single-layer cylindrical reticulated shells,and it studied the effect of substructure's stiffness on failure behaviors of reticulated domes. The numerical model with elastic substructure and cylindrical reticulated shells is built in which separated columns represent different stiffness of substructure. The full-range dynamic response analysis method is applied to investigate the failure characteristics of single-layer cylindrical reticulated shells with elastic concrete substructures under strong earthquakes. Failure modes of cylindrical reticulated shells with substructures are illustrated according to the stiffness of substructures. Based on the numerical calculations, the influence on the failure characteristics of the substructure is investigated and the reasons which cause the influence are discussed. Finally, the variation of ultimate load of cylindrical reticulated shells with respect to structural parameters is investigated through a comprehensive parameter analysis.3. Failure mechanism of single-layer cylindrical reticulated shells with steel substructures under severe earthquakesAfter the analysis of the effect of substructure's stiffness on failure behaviors, this paper carried out the study on failure mechanism of cylindrical reticulated shells with steel substructures under severe earthquakes. Firstly, the accurate and refined analysis model is built, in which the material non-linearity of the steel substructure is taken into account. Secondly, typical failure modes of single-layer cylindrical reticulated shells with the consideration of steel substructure are illustrated. Finally, failure discrimination criterion is proposed to estimate the ultimate load of single-layer cylindrical reticulated shells with steel substructures. It is observed that steel substructure has great influence on the failure mechanism of cylindrical reticulated shells under severe earthquakes.