Study On Seismic Performance Of Parabolic Single-Layer Cylindrical Reticulated Shells

Single-layer cylindrical reticulated shells structure is often used in the project,its beautiful curve form and easy construction are the main reason why it is widely used.The research results show that the ultimate bearing capacity of parabolic single-layer cylindrical reticulated shells is larger than that of single-layer cylindrical reticulated shells under static action.However,its performance under dynamic action,especially under seismic action,has not been studied deeply.So in this paper,the parabolic single-layer cylindrical reticulated shells is used as the object of study to analysis its seismic performance.Based on the study of the natural vibration of the parabolic single-layer cylindrical reticulated shells,the natural period of vibration and mode shape of vibration of the structure are obtained,whose characteristics are analyzed.Based on the nonlinear time history analysis of the structure,the seismic response of the structure under the action of horizontal,vertical and three-direction seismic waves is investigated.In the different ratio of rise to span,the maximum axial force of the members and the maximum displacement of the nodes in the three directions of X,Y and Z are compared under the action of El-Centro seismic waves,1'aft seismic waves and artificial simulation seismic waves,the study find that the response under the action of El-Centro seismic waves is the largest.The influence of the ratio of long to span,roof load and initial imperfection on structural seismic response are analyzed through the analysis of parameters.Under the action of frequent earthquake and rare earthquake,it is found that the parabolic single-layer cylindrical reticulated shells structure is better than the traditional single-layer cylindrical reticulated shells structure in reducing the axial force and the displacement of the nodes and improving the material utilization efficiency.In addition,the parabolic single-layer cylindrical reticulated shells structure is also better than the single-layer cylindrical reticulated shells in the amount of steel per unit area.Under the action of Taft and El-Centro three-dimensional seismic waves,the dynamic whole process analysis is carried out.The Load-the maximum displacement of node curve,the development of the plastic,the deformation of the damage,etc.are comprehensively studied,and the four characteristics of indicators are summed up such as the maximum displacement of the node,the proportion of more than 12.5%cross-section into plastic rods,the proportion of full-section into plastic rods,the value of average plastic integral point.In the Matlab software environment,the instructor and non-instructor neural network are used to classify 81 examples of reticulated shells.The results show that the two neural networks have accurate classification and prediction results,and the self-organizing competitive neural network has intuitive results.Self-organizing competitive neural networks have an intuitive result output,BP neural network can be very good to see the data slightly deviate from the conventional situation of data.