Research On Wind Load Characteristics Of Main Girder Of Gantry Crane And Wind Load Reduction Design

As an important logistics handling machinery,gantry cranes widely serve different areas of the national economy and occupy an important position in industrial production.Because of its large span and high height,its structure is very sensitive to wind loads,so the wind-induced effects of cranes cannot be ignored.Especially the southeast coast of our country is a typhoon-prone area.Research on the wind load of gantry cranes can effectively prevent and reduce the occurrence of accidents.Therefore,this article focuses on the goal of wind-resistant and load-reducing design of gantry cranes,and comprehensively uses CFD numerical simulation and wind tunnel test to analyze the wind-induced effects of cranes under different incoming wind angles and the characteristic parameters of the main girder(slenderness ratio,aspect ratio)on the wind-induced effects of cranes.The aerodynamic shape optimization measure of local opening is introduced into the field of crane structure design,which provides a new idea for the crane’s wind resistance and load shedding design.The main content includes the following aspects:(1)Through the methods of CFD numerical simulation and wind tunnel test,study and discuss the characteristics of the flow around the large gantry crane with different angles of the flow direction,analyze the flow characteristics of the flow field,and obtain the complete crane and its components.The surface pressure coefficient distribution and various aerodynamic parameters have improved and enriched the relevant content of the "Design ruler of cranes".Through comparison with the wind tunnel test results,the reliability and accuracy of the Realizable k-ε model turbulence model applied to the wind engineering problems of the gantry crane structure are verified.(2)The main girder is the main windshield component of the gantry crane,and its structure with different characteristic parameters(slenderness ratio,aspect ratio)is subjected to CFD numerical simulation.The surface pressure distribution and resistance coefficient of the structure under different working conditions are obtained,and the wind coefficient spectrum of the components in the "Design rules for cranes" is improved.Through comparison,it is found that the value of the code is relatively conservative,which is not conducive to the optimal design of wind loads.The law of the resistance coefficient of the main girder changing with the characteristic parameters is summarized,and suggestions are provided for the value of the characteristic parameters of the main girder from the perspective of wind resistance design.(3)The treatment of local opening is a common wind resistance measure in large structures,which is often used in high-rise buildings and bridges,but there are few studies on local opening of cranes.Based on this,this article introduces the local opening of this kind of aerodynamic shape optimization measure into the field of crane wind resistance design,and provides ideas for the crane wind resistance design.The influence of different methods on the wind-induced effect of the main beam is evaluated,and its load shedding mechanism is analyzed in combination with its pressure distribution,average streamline diagram,and average vorticity diagram.The results show that local opening measures can greatly reduce the impact and vibration of the incoming flow on the crane,and improve the stability of the structure in the wind field.It is an effective wind-resistant design method.