| Reliability of the new structure system of lattice type concrete filled steel tube windturbine tower is calculated. And its main failure path is also analyzed.First of all, statistical parameters and probability distribution of the resistance of eachcomponent and the load suffered by structure in the lattice type concrete filled steel tubewind turbine tower are calculated. The relation between the wind pressure and pneumaticthrust is deduced by Bernoulli equation. The statistical parameters of wind turbineaerodynamic thrust at the center are deduced by using the probability model of windpressure, which lay the foundation for the tower system reliability analysis.The reliability of concrete filled steel tube column which is important components oflattice type concrete filled steel tube wind turbine tower is analyzed by using ANSYSprogram and Monte Carlo method. The sensitivity of parameters which affect thereliability of concrete filled steel tube column was determined. The influence degree ofsteel tube’s thickness, load, concrete strength and the strength of steel decrease gradually.The research shows that the steel tube wall thickness should be controlled at first in orderto be sure the reliability. What’s more, costs can be reduced by changing the steel strengthand concrete strength when the reliability of structure is satisfied. The ultimate bearingcapacity of12axial compression concrete filled steel tube columns are carried on themathematical statistics analysis by Matlab software, which close to the logarithmic normaldistribution. According to the recommended formula is deduced from the statisticalparameter calculation expression of ultimate bearing capacity of concrete filled steel tubecolumn. Compared with the calculation results, it is found that the reliability index ofultimate bearing capacity is about15.5%larger than that of yield bearing capacity for theaxial compression concrete filled steel tubular column, so late bearing capacity reliabilityof concrete filled steel tubular column has great safety reserves. Mixed system model of the lattice type concrete filled steel tube wind turbine towerwas established. The main failure path of tower is found by using the global branch-bound method. The results show that the main failure path is focused on the three layers atthe bottom of the tower, there are no damage in tower leeward artifacts and cross diagonal,and the symmetric bar failure at the same time. The destruction of the tower begins fromthe compression oblique abdominal rod and terminates in the underlying tension pillar. It isfound that focusing on the bottom tower column and oblique abdominal rod should bestrengthened in future design and construction. The tower system reliability is0.9981byPNET method. Then the reliability of tower is also analyzed with ANSYS program andMonte Carlo method, the calculation result of reliability between the two methods ofcalculation differ by0.0003, which indicate the result obtained by PNET method is correct. |
PDF Full Text Request