Design Of Safe Early-Warning System For Roof Spatial Latticed Structure Of Wuhan Natatorium

Space latticed truss structures (Abbr. SLTS) are accepted as the economical and comfortable structures, as there are many advantages in SLTS such as high space stiffness, moderate stability, good earthquake resistance capacity, sound bearing capacity. On the other hand, due to magnitude dimension, subjected to too much random load, and exposing in bad environment, it is inevitable that load long-term effects, fatigue effects and unpredictable accident consequently resistant capacity of nature disaster descending influences employ function and eventually causes tragedy accident in extreme situation.In this thesis, the safe early-warning system of roof spatial latticed structure of Wuhan Natatorium is selected as practice background. The system consists of two assistant sections, i.e. automatic assessment work status safety of structural key rods sub-system and automatic alarm of firn thickness on latticed structure sub-system. The main contents are as follows:Firstly, the progress and relative theories of Structure Health Monitoring are introduced, the basic methods of reliability assessment are summarized and the problems demanding to be solved are put forward. Static analysis of roof truss structure subjected to design load is done, employing space link series FEA, and internal force distribution of truss structure may be realized to some extent. As SLTS are magnitude dimension, subjected to too much random load, and exposing in bad environment, it is necessary to study the impact of random input variables on SLTS. Analysis of the reliability of the spatial structure is discussed by applying the finite element method and the most influential random input variables are identified, which provide theoretical basis for the safe early-warning system.In the light of the respective characteristic of spatial structure, the method of seeking the key component of structure is expounded. The reliability of spatial structure is analyzed by the software ANSYS, and then the key rods are judged out. And a simplified method to evaluate the security of existing building structures is proposed. Hence the automatic assessment work status safety of structural key rods sub-system is designed.In order to realize the automatic alarm of firn thickness on the latticed structure, the snow load is identified real-timely by fuzzy pattern recognition theory based on data-acquisition from the strain gauges, which are installed on the skylight, since it is opt to accumulating snow in snowy days. It successfully realizes the recognition of snow load and auto alarm for security of the roof spatial latticed structure by informing the consumer timely.In the thesis, safe early-warning system of long-span spatial latticed structure during the period of service is designed. It successfully realized safe early-warning for large-scale spatial structure, and provided the scientific foundation for a method to reduce loss of life and property.