| The crane in the working process will be affected by different degrees of impact and vibration,will make the crane vibration,affect the safety of the structure,but also lead to the fatigue operation of the operator,taking certain control measures to reduce the vibration of the crane has important engineering application value.Taking 20 t double beam gantry crane as the research object,the vibration characteristics of the main beam of double beam gantry crane are studied by using ANSYS finite element software.According to the structural characteristics of the gantry crane,the structure of the dynamic vibration absorber is designed,and the dynamic parameters of the dynamic vibration absorber are determined.Finally,the purpose of reducing the vibration response of the crane is achieved.The specific contents are as follows:(1)According to the structural characteristics of the crane,the structure of the crane is simplified reasonably,and the parametric model of the 20-ton double-beam gantry crane is established by using the APDL language of the finite element analysis software ANSYS.(2)The modal analysis of gantry crane is completed,and the natural frequency and mode of vibration of crane are obtained.The key natural frequency and mode of vibration corresponding to lifting braking and running braking of crane are further determined.On this basis,the simplified dynamic model of crane is obtained.(3)In order to attenuate transient vibration caused by crane braking rapidly,the influence of dynamic vibration absorber parameters on the characteristics of dynamic vibration absorber was analyzed,and the optimal parameters of dynamic vibration absorber were determined.A special three-way dynamic vibration absorber was designed and used in the simplified equivalent mechanical model of crane,and the dynamic vibration absorber system model of crane was established.(4)According to the determined parameters of dynamic vibration absorber,the finite element model of the crane with dynamic vibration absorber is established.The transient response analysis of the dynamic characteristics of the gantry crane is carried out by using the perfect method in ANSYS.Two working conditions are considered in the analysis,namely,dolly brake,cart brake,and cart brake.The dynamic characteristics of the crane before and after the installation of the dynamic vibration absorber are obtained.The results show that the installation of the dynamic vibration absorber can effectively reduce the vibration response of the gantry crane. |
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