Dynamic Characteristic And Study On Earthquake Response Of The Beam String Structure

Beam string structure is one of the new pre-stress steel structure styles, because it possessed of rational mechanical feature, it has been used in many national and foreign engineering practices. This paper analyses dynamical characteristic and seismic characteristic of the beam string structure by theoretical calculation and experimental research. And analyses different parameters produce the impacts to static and dynamical behavior of the structure. The main issues in the paper are:Design model of one-way and bi-direction beam string structures, and analyses modal of beam string structure by sap2000. This paper has system analysis for free vibration of structure. And analyses different parameters produce the impacts to free vibration of the structure.The bi-direction beam string structure natural vibration characteristics experiments are researched in this paper. Because the reality modes of structure mostly are vertical direction arch truss vibration, so model vibrations in outer plane are restricted in analysis. In experiment, the front three modes of vertical directions are achieved through vibration exciter in the structure. Depending free vibration attenuation curve can achieve damping ratio characteristics. This paper analyses the impacts of different restrains, different loads and different pre-stress value of cable on the natural vibration frequency, damping ratio and mode of structure. The experiment results are compared with the finite element analysis results, they inosculate well.This paper has system analysis to dynamical response of beam string structure under earthquake. And analyses ratio of rise to span,sag ratio, number of brace rod and pre-stress value of cable produce the impacts to seismic characteristic of the beam string structure. First , calculate and analyses earthquake response of one-way and bi-direction beam string structure by method of response spectrum ,and check vertical earthquake response by the time history analysis ,finally simply discuss different parameters produce the impacts to the structure.This paper studies the mechanics behavior of pre-stressed arch truss string structure through analyzing the multi-stage pre-stressing loading experiment, vibration exciter experiment, shaking table test results, also through static and dynamic theory calculation results. The conclusions are achieved correspondingly, the problems should studied are prospected by the paper.