Analysis Of Free Vibration Characteristics And Seismic Response Of H-radiant Beam String Structure

Beam string structure is a kind of rigid and flexible hybrid structure composed of the upper beam(truss),the strut and the chord cable.It is a new type of self-balanced spatial structure system.The Beam String structure has the advantages of force reasonable and simple construction and so on.It has been widely used in long-span structures in recent years.As one of branches of the beam structure,radial beam string is more suitable for large-scale activities center,stadium and other building structures.Based on the published articles,this paper has studied the natural vibration characteristics analysis and seismic response analysis of radiant Beam String Structure.The main contents are summarized as follows:(1)According to the completed actual project,the finite element model of the radial H-beam string is established by using the APDL language in ANSYS(the first model),and then the second model is developed which is different from the first model in spans.(2)The linear relationship between temperature and prestress is obtained by the equivalent cooling method,and the reasonable temperature drop of the fixed structure is determined according to the target prestress value.(3)The vibration characteristics of the structure are analyzed,and the vibration modes and frequencies of the structures under different parameters such as sounding ratio,sag ratio and temperature drop are analyzed and compared.Meanwhile,by analyzing the self-vibration characteristics of the two models with the same sagittal ratio,the sag ratio and the prestressing value in different span cases,this paper laid a foundation for the subsequent dynamic analysis.(4)Based on the actual engineering situation,the seismic response of the structureunder different seismic waves is studied by time history analysis.At the same time,the seismic response of the structure under different parameters is analyzed,that is,the effects of different sagittal ratio,sag ratio and cooling value on the structural displacement,the axial force of the strut and the internal force and bending moment.(5)Through the above analyses,we found that the maximum displacement of the structure is not at the center of the roof,and increasing the structural vector span ratio,vertical span ratio and reasonable prestressing value in the earthquake process can reduce the vertical displacement of the structure and enhance the overall stiffness of the structure and so on.These conclusions will provide theoretical reference for practical engineering applications of such structures in the future.