NUMERICAL SIMULATION AND FORCE PERFORMANCE ANALYSIS OF WIND-INDUCED COLLAPSE OF SUPER LARGE COOLING TOWERS

Historically, the wind-induced collapse of large-scale cooling tower has occurred many times under the action of strong winds. Most studies focus on local strength overrun or instability of wind-induced towers, and ignore the subsequent phenomenon of overall continuous collapse caused by local damage. It is difficult to reveal the wind-induced collapse process and mechanism of large cooling towers. In view of this, based on CFD and LS-DYNA technology, a numerical simulation method for wind-induced collapse of large-scale cooling towers was proposed. Taking the highest large-scale cooling tower in the world as an example, which is 220 meters high and local in the Shanxi Lu'an Power Plant. A three-dimensional finite element model considering material nonlinearity was established, and the dynamic characteristics of the structure were analyzed. Subsequently, based on the dynamic time history analysis method, the three-dimensional average wind pressure of the tower obtained by CFD was loaded to carry out the pseudo-dynamic analysis, and the whole process of wind-induced collapse of the super-large cooling tower was reproduced. Finally, the characteristics of the variation of the stress distribution of the tower and the distorted deformation posture of the whole collapse process are studied. The force characteristics and mechanism of the wind tower collapse caused by the cooling tower were discussed, as well as the influence of the unit failure parameters. The results verified that the numerical method can effectively simulate the whole process of wind-induced collapse of super-large cooling towers. The collapse process begins with large deformation of the windward side of the tower throat and wrinkles in the range of 30° on both sides, and finally the deformation is uncoordinated, which resulted in collapsing into each other. The study indicated that the mechanism of collapse of large-scale cooling tower caused by strong wind can be divided into bending mechanism and hanging strand mechanism. The influence of unit failure parameters of material model on wind-induced collapse of super-large cooling tower cannot be ignored.