Research On Optimal Selection Of Super-long Span Suspension Mega-latticed Structure

Throughout the history of architecture,the pursuit of long-span architectures has never ceased.Especially in recent centuries,along with the application of high-performance materials,the span records of buildings have been constantly refreshed.However,with the continuous growth of the span of the structure,it can not meet the requirements of the safety and economy of the structures very well only by increasing the section of the components and strengthening the strength of the material,so it is necessary to seek a breakthrough in the form of the structure.Combining super-long-span suspension bridge with the traditional long-span structure forms,suspension mega-latticed structure makes it possible to realize the super-long-span structure with kilometric scale,and its mechanical and economic performance deserves further exploring.With the help of finite element analysis software ANSYS,the whole parametric models of five kinds of suspension mega-latticed structures with the span of 1000 m were established.The initial shape of the structure was analyzed,and the initial shape of the structure and the internal prestressing force of the suspension cable were obtained accurately.On this basis,the static performance and stability performance of the five kinds of suspended mega-latticed structures under various load conditions were analyzed.Detailed modeling and analysis of the pylon were completed,which improves the overall model.The influence of geometric parameters on the mechanical properties of the structure was studied.Finally,the overall stability of the structure after a single cable break was investigated.The main contents are as follows:First of all,the geometric and topological relationships of Rib mega-latticed structure,two kinds of Schwedler mega-latticed structure,Kiewit mega-latticed structure and Three-dimensional grid mega-latticed structure were analyzed.Correspondingly,the arrangement forms of suspension structure were designed and five kinds of suspension mega-latticed structure automatically and parametrically modeling program were worked out.Through the analysis of the self-weight load of the lower mega-latticed structure,the initial shape and initial internal prestress of the upper suspension structure were obtained.On this basis,the static performance of each structure under 12 load conditions was analyzed,and the control load condition was obtained.The influence of asymmetrically distributed load on the structure was studied.The overall stability of the structure was investigated through the whole process of load-displacement analysis.Combining with the above analysis,a better structural form was synthetically selected.To improve the whole suspension mega-latticed structure model,the fine modeling of the pylon was carried out.Through analysis of the important parameters such as the inclination degree of the tower column,the number and location of the crossbeams and the stiffness ratio of the crossbeam and column,the form of the pylon was constantly optimized.A kind of economical and applicable pylon was designed,and the mechanical performance of the mega-latticed structure model before and after the refinement of the pylon model were compared and analyzed.At last,aiming at the control parameters of suspension mega-latticed structure,such as rise-span ratio of mega-latticed structure,the regularity of the static performance of the structure was analyzed,and the reasonable range of the structural design parameters was concluded.By means of static and transient analysis methods,the overall stability of this kind of structure after a single sling breaks was compared and analyzed.