The Gantry Crane Dynamic Research Based On Beam Theory

The dynamic response in the work process of crane is an important subject in crane dynamic study. With the rapid development of mechanical engineering, the demand of gantry crane is constantly increasing, vibration problem cannot be ignored in the course of its work. Though there have been a lot of research about gantry crane dynamics, these researches rarely combined with beam theory, and there are still many problems to be studied further in these aspects.This paper use gantry crane as the research object, respectively based on Euler-Bernoulli beam theory and Timoshenko beam theory, combined with the structure dynamics, numerical analysis method, the finite element method and some other related theory, the main girder structure-trolley coupling vibration model and structure-trolley-load coupling vibration model are established to study its vibration characteristics. At the same time, with the dynamic simulation software, the dynamic simulation of the crane is analyzed. The main contents include:First, Based on Euler-Bernoulli beam theory, ignored the transverse shear deformation, the crane girder structure and trolley coupling vibration model is established, and the coupling vibration system differential equation is deduced. With the numerical analysis method, the equations are well solved. With the further research, the change rule of the system's natural frequency according to the position change of the car is given.Second, using Lagrange equation, the trolley and load system dynamics equation is established, the factors which lead to load swing are analyzed. Gantry crane structure-trolley-load coupling vibration model is established according to practical work process. Considered with the effect of the rotating and shearing deformation on the beam, based on Timoshenko beam theory, the differential equations of coupling vibration system is established. Through the finite element method, the gantry crane structure modal is got, this parameter is substituted in the coupling vibration system equation, and finally the numerical solution of the vibration differential equation is got by the numerical analysis method, then the coupling vibration system vibration characteristics are analyzed. Third, by the means of CAD software SolidWorks, the three-dimensional entity model of gantry crane is established. By importing the model into finite element analysis software ALGOR, the gantry crane dynamics simulation analysis is done, the different dynamic responses of the crane girder's natural frequency as the movement of the trolley are obtained, such as natural frequency and vibration mode, and the obtained results are further analyzed. Meanwhile, the results which is got by the entity modeling and beam element modeling is compared and analyzed. Through nonlinear material movement simulation analysis in the ALGOR, the rigid-flexible coupling dynamics simulation is done, and the response of the crane girder due to the trolley's movement is also studied in this process.