Study On Wind Load Calculation Of Tower Crane In Non-working State

Tower crane plays an important role in modern construction.With the acceleration of urbanization,the construction input quantity of tower crane also increases.The erection height of tower crane and the length of lifting arm in the market also increase.Among many accidents,the collapse and toppling caused by special weather in non-working conditions have always been concerned,and the role of wind load of the tower cannot be ignored.At present,finite element calculation is mainly used in the research on the wind load of tower crane at home and abroad,and wind tunnel test is also used in some of the research.However,in the actual design and calculation of tower crane,national standards and industry standards are used in calculation.At the present stage,tower crane design in China is mainly completed by referring to several standards,such as GB/T 13752 tower crane design code,GB/T 3811 crane design code,GB/T 5009-2016 building structure load code,etc.GB/T13752 is still in the transition stage between 1992 and 2017 versions.However,the calculation results given by the current standard are different,and the research on wind load calculation of tower crane is relatively lagging behind.In this paper,the tower crane is taken as the research object.The differences between the current standards for tower crane design and calculation are analyzed,and the influence of various parameters on the calculation results is obtained.In addition,on the basis of computational fluid dynamics(CFD)and statistical analysis method,the wind field characteristics of tower crane structure in non-working state and the influence of different structures on the wind field characteristics are studied by using ANSYS Workbench and Fluent software.Finally,the wind load and wind load coefficient corresponding to different mechanism forms are calculated.(1)In this paper,according to the current design codes and standards of tower crane,the method of parameter selection in the design and calculation of wind load of tower crane under non-working condition is studied.In this study,the error analysis theory in mathematics is used to compare the calculation results of non-working wind load of each standard under the same conditions,and the calculation differences of each standard are analyzed combined with the calculation results.(2)The establishment of a flow field model to simulate the wind field characteristics of a tower crane structure.The simulation of the wind field requires the establishment of a correct flow field model.Therefore,the wind field flow model of the tower body and the boom of the tower crane was established using Solid Works and Design Model.By setting parameters such as boundary conditions and fluid models,the simulation is brought closer to the real situation.(3)Wind field simulation of tower crane structure.Based on the theory of computational fluid dynamics(CFD),the wind field of tower crane with different structure and different wind direction angle is simulated by FLUENT software and K-? model.The distribution cloud chart of surface wind pressure,section velocity and velocity vector of tower crane body and boom under different wind direction angle is obtained.In addition,the variation of wind field characteristics corresponding to different wind direction angles is also analyzed.(4)Influence of truss structure on wind load characteristics of tower crane.Based on the established tower crane model,the shape and layout of structural steel sections is change to obtain the distribution cloud diagram of different wind pressure,section velocity and velocity vector.Wind load coefficients of different structures were calculated and compared with current standards.