Seismic Analysis And Shock Absorption Research Of Gantry Crane Based On Seismic Time History Method

The frequent occurrence of earthquake disasters seriously threatens human survival and economic development.The gantry cranes that are widely used in earthquake-prone ports,docks and freight yards will cause huge loss of life and property once they are damaged or even collapsed under earthquake loads.At present,the research on earthquake resistance and shock absorption of structures has been greatly developed in civil engineering.However,the research on the earthquake resistance and shock absorption of the crane is basically lagging behind.Therefore,this paper aims at the shortcomings of low calculation accuracy and large amount of calculation in the traditional structural seismic design method and the improvement of the overall seismic performance of the structure.The research work on the metal structure of a large-span portal crane mainly leads to the following conclusions:(1)Through the ANSYS finite element analysis software,a three-dimensional model of the metal structure of a large door machine is established.From the static load analysis results,it can be seen that the stress and deformation of the structure under different working conditions can meet the allowable requirements,indicating that the door machine can meet conventional loads.Under the job requirements.In addition,the modal response data of the door machine was extracted through modal analysis to provide data support for time-history analysis and shock absorption research later.(2)Based on the basic theory of seismic time history method,synthesize 3seismic time history curves that conform to China’s standard response spectrum.By comparing and analyzing the seismic response results of the door machine metal structure under the seismic time history method and the IDA method: the seismic response results of the structures obtained by these two methods can be well matched,proving that the seismic time history method is a new method.The simplified seismic analysis method can well predict the seismic response of the structure under different earthquake intensities.(3)Based on the engineering structure shock absorption control theory,a shock absorption device designed in accordance with the door machine structure in this paper is designed.A systematic analysis of the dynamic characteristics of the door machine with and without shock absorber found that: compared with the door machine without shock absorber,the stress response of each node of the door machine with shock absorber and the corresponding natural vibration period response spectrum The overall value is reduced by about 75%,which proves that the shock absorber can effectively reduce the structural seismic response.(4)Guided by the core idea of analyzing the ultimate seismic resistance of shock-absorbing door machines.First,input the seismic time-history curve with peak acceleration of 2G,so that the seismic response of the damping door machine basically reaches the maximum allowable stress.Then,the evaluation system of peak acceleration,stress and deformation under seismic load of shock-absorbing door machine is established.Under the requirements of the operating environment and safety level of the door machine,compared with the non-vibration door machine,it can resist 0.4G ground vibration,and the damper door machine can resist 0.7G ground vibration,which greatly improves the door machine’s seismic performance.