Research On Dynamic Design And Optimization Of The Structure Of Gantry Crane Based On ANSYS

The integration of the global economy and the sustained growth of the foreign trade in our country have given further impetus to the explosion of the logistics industry of harbor in our country.Therefore,our requirement for the port crane which is the most important tool of the logistics of the harbor is higher and higher. Specifically,we demand the rated load lifting capacity of the hoisting machinery to be lager,and the running speed of it to be faster.Besides,there are many unstable states,including the lifting start,lifting break,starting unload,laying down start, laying down break,unloading suddenly,the collision of the gantry,the starting and breaking of the trolley,when the port crane is working.In these states,the structure and the mechanism are influenced in varying degrees by shock and vibration.As a result,we must concern the influence caused by shock and vibration and using dynamic design method when we design hosting machinery.But the static strength has been regarded as the main design standard in port crane design for many years.In this way,we multiply the static load by a dynamic coefficient,and regard the result as the dynamic load.Actually,it is still a static design method.Most FEM analysis of the crane in our country is aim at the bearing capacity of the structure.And usually we use fractional step method to do the FEM analysis of the crane.According to fractional step method,we could reduce the difficulty of creating the FEM model by decomposing the structure of the crane to parts,and connecting the FEM model with reaction force.The result of the analysis in this method is hard to reflect the dynamic performance of the cane exactly because the connections between parts are simplified.This thesis is based on dynamic analysis theory and FEM calculating method.It create the FEM model of the gantry crane,and complete the model analysis and transient analysis of the model and obtain the former ten rank of the natural frequency and the mode of vibration and the dynamic coefficient of the lifting start state.The thesis mainly includes: According to the crane dynamic theory,this thesis utilizes the ANSYS software to create the FEM model with shell element,solid element and combination element. It analyze the FEM model and obtain the former ten rank natural frequency and the mode of vibration.It also completes the transient analysis to obtain the dynamic response of the structure in the lifting start state.At last it create the FEM model of the structure with beam element and optimize it according to the result of the transient analysis.In a word,dynamic analysis of gantry crane applies advanced design and analysis in design of bridge crane and offers efficient tool and method to design bridge crane that much more economic,credible,stable and with high performance.