Health Monitoring And Analysis Over Construction Process For Large-span Complex Steel Structure

In recent years,large-span complex space steel truss structure been havedeveloped very quickly in the domestic because that some adcantages,such asmodeling beautiful,good economy and high industrial construction can be found in thebuilding.Novel large space structure,such as large stadium,large gymnasium,exhibitioncenter been saw by people.But,because of changeable environment and complex stresssituation,the structure be easily damaged and destroyed,in the constructionstage,especially.There are very important practical significance and academic value inreal-time online health monitoring and diagnosis and early warning research oflarge-span steel strcture during construction.The meaning of the research becomelarger,because that the complete system of the research and application about the aboveproblems at object home and abroad has not formed.The research object of this paperis the steel roof of Xining gymnasium,and the main contents are as follows:(1)The structure health monitoring system consists of the overall frame and thefunction of each part were studied in this paper.The constitute,the purposes and theadvantages of the sensing elements are briefly introduced and the working principle ofthat are researched.This sensing elements contains resistance strain gauge,optical fibergrating sensor,the structure of the steel string sensor,that were used commonly in theengineering practice.The working principle of the measuring instrument are studiedpreliminarily.The measuring instrument contains the static water level and thetachometerthat were used commonly in the engineering practice.(2)The monitoring system of Xining gymnasium was reasearthed,and themonitoring and measuring points arrangement scheme and the sensor selection planwere determined in this paper.The stress,deformation and temperature of Xininggymnasium in the whole construction process were measured in real-time on-linemonitoring,and the monitoring results were analyzed.The analysis results showthat:monitoring obtained a better effect,high accuracy,good stability,and themonitoring results conform to the actual law.The monitoring data show that:the steelstructure of Xining gymnasium is in working order,and the stress distribution of thestructure is reasonable,and the structure deformation is in allow range.The above showthat the construction technology of the steel roof of Xining gymnasium accords withrequirement;the construction quality is good;the stiffness reserves rich;the structure issafe.(3)The steel structure of Xining gymnasium was simulated using the ANSYSfinite element software in this paper.And then,the simulation results and the practical monitoring results were compared and analyzed.The contrast analysis results showsthat the simulation values coincides with the monitoring values,both of the stressincrease in the overall trend.The selection of the monitoring key points and parts tothis project monitoring system is reasonable and effective,which can provide referenceand mirror for the measure points arrangement of the later similar projects.(4)The natural vibration characteristics of the whole steel roof of Xininggymnasium were analyzed using the ANSYS finite element software in this paper.Theprimal20order frequency and vibration model of the steel structure were extracted andanalyzed.The analysis results show that the wrest resistant performance of the steelroof is better and the quality and stiffness distribution of the whole steel roof areuniformity.The spectrum is very intensive,and the natural vibration characteristics isrelative complex.The dynamic response of the structure is more accurate reflected oncondition that relatively more vibration model participate in combination calculation inthe earthquake action or wind load.Finally,all researches in this article are concluded.Some favorable conclusions areobtained and some questions need to be solved in future are point out.