Dynamic Response Analysis Of Tower Crane Under Wind Loading And Hositing

With the development of economy and society,the type of tower crane advances towards the tower body higher,tower arm longer,and the weight heavier in order to adapt to the needs of engineering construction and logistics transportation.Then, challenges to the designing calculation and security operation of crane also come from them. Because the tower body is higher, the influence of the wind load on structure become bigger, then the wind isn’t considered as the static load. Whlie the tower arm is longer and the weight is heaviver, mechanical impact vibration become more violent. The above external excitation may cause the vibration of the structure, and the analysis of vibration response has a guiding significance on design and operation. QTZ25tower crane is utilized for example to carry on the analysis.In establishing the tower crane model,this paper combines less degrees of freedom method with finite element method to simplify the number of degrees of freedom.Then,the simplified model is established based on the known FEM software-ANSYS.While selecting lifting condition,unloading condition,0°wind condition,90°wind condition,lifting and0°wind condition, unloading and0°wind condition,lifting and90°wind condition, unloading and90°wind condition carry on the analysis.Among them,the impact excitation of lifting and unloading condition is used by dynamic load coefficient method with reference to "the crane design standard"(GB3811-2008).For wind load condition, this paper uses linear filter method to simulate turbulent wind velocity and then get wind load. In order to get an intuitionistic results,The loading process is divided into initial smooth,impact and vibration response of three stages.On the analysis of vibration response,for lifting condition and unloading condition,this paper extracted8point displacement response of the crane boom to analyze impact excitation on the influence of the boom.For the remaining conditions, this paper analyze the results of the overall structure.In order to simplify and improve the efficiency of quantity,it only extract tower crane9point (along the tower body6 points, the tower arm3point) to observe the displacement response.Furthermore,the stress changes is also very important in the analysis,and the tower crane is made up of many standard sections.The stress changes of these section may lead to danger. Therefore, this study extract these55sections to observe stress time history response.Analyzing these responses may find that: under the action of impact excitation, the boom may reduce from far to near, and the larger stress can be found in the joint of boom and pull rod.Under the action of wind load,the displacement vibration rule of the crane tower is consistent and the vibration amplitude is increasing from low to high.Under the coupled action,when the wind and lifting plane are parallel,the vibration response of the structure will mutate, and vibration amplitude of lifting coupling condition is maximum;when the wind and lifting plane are vertical,the results with the wind condition alone are the same.