Health Monitoring Research Of Space Big Span Structure

The development of large span structures is one of important symbol for ameasure of national building scientific and technological level. However, how can weensure the security of these long-span structures in the construction and service stagehas been the research hotspot? The steel roof of Xining Stadium is used steel pipetruss structure system, which is one of important member of the large span spatialstructures. Real time on-line monitoring is done for bracing unloading of steel roof，loading of roof board， and subsequent long-term service stage to ensure theconstruction safety of structure and normal use. Meanwhile, the effectiveness of thewhole system in the monitoring process is proved.Firstly, the monitoring systems of large span structures are introduced andtaking Xining stadium as an example in this paper. Stress-strain of system ismonitored by fiber grating sensor and vibrating wire sensors. Deformation of systemis monitored by total station and static force level. Meanwhile, the vibration,temperature and wind speed is monitored in the service stage.Secondly, the monitor of temporary bracing unloading of large span structuresis researched. The stress and deformation in the temporary bracing unloading processis simulated by ANSYS10.0, and comparative analysis with practical monitoring data.Although the value of simulation will be different from practical monitoring data, butits stress and deformation is monitored within the scope of the structural design. Andprovide reference for unloading of similar projects future in the future.Finally, still taking Xining stadium as an example, the quality and healthmonitoring of were introduced and analyzed when loading construction of large spanstructures roof.The real-time monitoring analysis of roof loading showed that: micro-strain deviatediscreteness of structure bar sometimes has more changes because the impact of hightemperature difference and indefiniteness of construction loads uncertainty factorsand so on in Xining. But the monitoring bars within the range of flexible working,have not reached the stress design value of the structural material (345MPa).