The Discussion Of Initial Geometric Imperfection Simulation Method On Single-Layer Spherical Lattice Shell In The Dynamic Analysis

Lattice shell in the process of processing transport installation would inevitably lead to node deviation and bars' initial bending,and the geometric defects are random,a single node in different direction and different sizes of deviation may cause different effects in the structure,the different combination of all the nodes make more results,the bars' initial bending is same.In order to a higher precision and efficiency,determine the defect simulation method is very necessary before the study of lattice shell dynamic performance impact with Initial geometric imperfection.This defect simulation method can achieve the ideal state is to be able to instead of most of the defects in adverse in the dynamic analysis.Currently the lattice shell initial geometric imperfection method is not yet mature in the dynamic analysis,mostly scholars use "Buckling consistent defect modal method" which is commonly used in static analysis and also some people use "Vibration consistent defect modal method",but for its rationality is not enough.Based on the reading of related materials for research,in the dynamic analysis of the single-layer spherical reticulated shell initial geometric imperfection simulation method are discussed,mainly do the following work:Firstly,through the secondary development of ANSYS software implements the Lattice shell node deviation and early bar bending random arrangement and arrange along the structural buckling modal and vibration model.Secondly,using the OpenSees finite element software do elastic dynamic response analysis of single-layer spherical reticulated shell with Random node deviation,Considering the influence of seismic wave type,the results show that:node deviation have little impact on the single-layer spherical reticulated shell in the elastic dynamic analysis.Make elastic-plastic dynamic response analysis on Single-layer spherical reticulated shell with node deviation applied by Buckling consistent Defect Modal Method","Vibration consistent defect modal method" and random arrangement method,the results show that:under dynamic action the structural response is completely random,"Buckling consistent Defect Modal Method" and"Vibration consistent defect modal method" are not effectively to simulate Lattice shell node deviation.Finally,using the OpenSees finite element software do elastic dynamic response analysis of single-layer spherical reticulated shell with bars' initial bending,Considering the influence of seismic wave type,the results show that:bars' initial bending have little impact on the single-layer spherical reticulated shell in the elastic dynamic analysis.Make elastic-plastic dynamic response analysis on Single-layer spherical reticulated shell with node deviation applied by Buckling consistent Defect Modal Method","Vibration consistent defect modal method" and random arrangement method,the results show that:under dynamic action the structural response is completely random,"Buckling consistent Defect Modal Method" and"Vibration consistent defect modal method" are not effectively to simulate Lattice shell bars' initial bendingThe finding by analysis is that:initial geometric imperfection have little impact on the single-layer spherical reticulated shell in the elastic dynamic analysis.In the elastic-plastic dynamic analysis "Buckling consistent Defect Modal Method" and "Vibration consistent defect modal method" are not effectively to simulate Lattice shell initial geometric imperfection,so before determining the initial geometric imperfection of lattice shell,we must carry out plenty of simulated random defects,and then determine a initial geometric imperfection with certain assurance.