The Metal Structure Dynamics Research On Gantry Crane

The development of cranes faces towards macro-scale operations technology; speed up, automation and intelligence. Men asking for Cranes capability are more and more exigent. People are desired the crane not only has a light weight, strong stiffness, big working space, but also has a high speed of the dolly and the cart, high operating efficiency. So it must advance the dynamics of the crane. Because of the crane being bigger and the dolly and the cart being speeding faster, it will bring great effect to the dynamic characteristics of the crane, and on the contrary the dynamic characteristics of the crane also will bring effect to operating efficiency. It is an inconsistent Phenomenon, and it will be more outstanding with the societal development. Now crane dynamics has been a hotspot of enterprises and colleges and universities.The gantry crane's similar working point is that it often start-up and retard. When the gantry's working status of the start-up,retarding or others changes, the mechanical system will generate strong impact and vibrate. Therefore, the mechanical system 's dynamic problem mainly studies them at start-up and retarding or other work appearances change suddenly the flexible vibration regulation of the system, on these grounds makes sure the motive of the system response. Pointed to the gantry crane's strong impact and vibrate while the loads are lifted off the ground suddenly, based on the mechanic vibration theory and finite element method(FEM), and using the FEM simulation software-ANSYS, this dissertation studies the numerical simulation of the Gantry structures as the vehicles lifting loads and it's dynamics emulation and responses while the Gantry is lifting and develop a relevant Gantry kinematics and dynamics numerical simulation software. The main research contents and results of the dissertation are as fellows:Firstly, the paper has investigated finite element theory,dynamic design theory,crane dynamics. It analyzes and investigates gantry crane structure. The paper establishes the scientific and optimized finite element computing model. It insures that the computation gets analysis results more accurate.Secondly, through the modal analysis on the structure of gantry crane with the Block Lanczos method, the first ten natural frequency and vibration modes are calculated when the trolley with full loads in the middle of the span; also analyze the frequency and vibration modes.Thirdly, through the transient response analysis with the FULL method, the displacement, velocity and acceleration time course responses in the middle of the span are calculated when the structure comes under the lifting impact load and the trolley with full load is in the middle of the span. In addition, the varying laws between the dynamic coefficient of the lifting and the lifting velocity are discussed.Fourthly, according to the result of the transient response analysis, calculate the lifting dynamic load factor and contrast with the experiential value which is calculated by the criterion commendatory formula; get the seventh frequency and contrast with the corresponding result of the modal analysis; contrast the steady value with the static value and so on.