Analysis Of The Mechanical Properties Of Cylinderical Reticulated Mega-structure Based On Sub-structure Stiffness

Cylinderical reticulated mega-structure is made up of main-structure and sub-structure.The first level is main-structure which belongs to big grid structure system,and its major functions contain bearing the load of the over-all structure and passing the load to supporting structure.While the sub-structure which belongs to regular grid structure is the second level,sub-structure carrying the partial load is located in big grid of the main-structure.This structure system has advantages of clear force’s transfer road,full use of material,easy installation and obvious economic benefits.In conclusion,the structure system will have good application prospects.The APDL language of ANSYS is used in this thesis to establish the model and calculation analysis.Based on the changes of sub-structure stiffness,considering the structure which bearing separately and bearing collaboratively,cylinderical reticulated mega-structure with sub-structure ofl atticed intersected cylindrical shell(LICS)and space truss are analysed and calculated in the article.The following is the main contents of the research:(1)The static property of cylinderical reticulated mega-structure with two sub-structure forms under four different load combinations is analysed from node displacement and bar systems internal force.Not only four points support and surrounding support of space truss sub-structure are considered,but also parameter analysis of rise-span ration and cross-sectional area of LICS are carried out.(2)Stability is the key problem in design of spatial latticed shell,so the eigenvalue buckling analysis and nonlinear buckling analysis which refers to geometric nonlinearity and material nonlinearity are carried out.The influence of the sub-structure stiffness is analyzed and main characteristic parameters(sub-structure form,sub-structure rise-span ration,sub-structure height,sub-structure cross-sectional area,sub-structure boundary constraint)of sub-structure are selected to carry out the eigenvalue buckling analysis and nonlinear buckling analysis.Accordingly,the structure ultimate load-carrying capacity with various parameters changes is obtained and the load-displacement curve is drawed.Also,make a study on the stability of the structure with considering initial geometric defects and uniform load of half span.(3)Considering the structure bearing separately and bearing collaboratively,the natural vibration characteristics of structure is analysed.And do a research on the influence of structural fundamental frequencies with the changes of sub-structure’s main parameters.(4)Using the surperpostion response spectrum method and time-history analysis method to carry out the structural dynamic analysis.Under the earthquake action of X,Y,Z one-way and three directions,this thesis analyses the changes of bar systems internal force and node displacement,as well as the response of the structure under the earthquake action based on the changes of sub-structure stiffness.At last,some conclusions are summarized according to the main contents and some aspects are given which can be improved continually.